100 TIME-SAVING SEARCH ENGINES FOR SERIOUS SCHOLARS (REVISED)

Some services have moved on, others have been created, and we’ve found some new discoveries, too. Many of our original 100 are still going strong, but we’ve updated where necessary and added some of our new favorites, too. Check out our new, up-to-date collection to discover the very best search engine for finding the academic results you’re looking for.

General

Need to get started with a more broad search? These academic search engines are great resources.

iSEEK Education:
iSeek is an excellent targeted search engine, designed especially for students, teachers, administrators, and caregivers. Find authoritative, intelligent, and time-saving resources in a safe, editor-reviewed environment with iSEEK.
RefSeek:
With more than 1 billion documents, web pages, books, journals, newspapers, and more, RefSeek offers authoritative resources in just about any subject, without all of the mess of sponsored links and commercial results.
Virtual LRC:
The Virtual Learning Resources Center has created a custom Google search, featuring only the best of academic information websites. This search is curated by teachers and library professionals around the world to share great resources for academic projects.
Academic Index:
This scholarly search engine and web directory was created just for college students. The websites in this index are selected by librarians, teachers, and educational consortia. Be sure to check out their research guides for history, health, nursing studies, criminal justice, and more.
BUBL LINK:
If you love the Dewey Decimal system, this Internet resource catalog is a great resource. Search using your own keywords, or browse subject areas with Dewey subject menus.
Digital Library of the Commons Repository:
Check out the DLC to find international literature including free and open access full-text articles, papers, and dissertations.
OAIster:
Search the OAIster database to find millions of digital resources from thousands of contributors, especially open access resources.
Internet Public Library:
Find resources by subject through the Internet Public Library’s database.
Infomine:
The Infomine is an incredible tool for finding scholarly Internet resource collections, especially in the sciences.
Microsoft Academic Search:
Microsoft’s academic search engine offers access to more than 38 million different publications, with features including maps, graphing, trends, and paths that show how authors are connected.
Google Correlate:
Google’s super cool search tool will allow you to find searches that correlate with real-world data.
Wolfram|Alpha:
Using expert-level knowledge, this search engine doesn’t just find links; it answers questions, does analysis, and generates reports.

Meta Search

Want the best of everything? Use these meta search engines that return results from multiple sites all at once.

Dogpile:
Find the best of all the major search engines with Dogpile, an engine that returns results from Google, Yahoo!, and Bing, with categories including Web, Images, Video, and even White Pages.
MetaCrawler:
MetaCrawler makes it easy to "search the search engines," returning results from Google, Yahoo!, and Bing.
Mamma:
Check out the mother of all search engines to pin down the best resources on the web. Mamma even searches Twitter and job postings!

Databases and Archives

Resources like the Library of Congress have considerable archives and documents available, and many of them have taken their collections online. Use these search tools to get access to these incredible resources.

Library of Congress:
In this incredible library, you’ll get access to searchable source documents, historical photos, and amazing digital collections.
Archives Hub:
Find the best of what Britain has to offer in the Archives Hub. You’ll be able to search archives from almost 200 institutions from England, Scotland, and Wales.
National Archives:
Check out this resource for access to the National Archives. Find online, public access to find historic documents, research, government information, and more in a single search.
arXiv e-Print Archive:
Cornell University’s arXiv.org offers open access to a wealth of e-prints in math, science, and related subjects. Search this resource to find what you need among 756,133 documents and counting.
Archivenet:
An initiative of the Historical Centre Overijssel, Archivenet makes it easy to find Dutch archives and more.
NASA Historical Archive:
Explore the history of space in this historical archive from NASA, highlighting space history and manned missions.
National Agricultural Library:
A service of the U.S. Department of Agriculture, you can find global information for agriculture in the National Agricultural Library.
Smithsonian Institution Research Information System:
Get access to the considerable resources of the Smithsonian Institution through the Research Information System, a great way to search more than 7.4 million records from the Smithsonian’s museums, archives, and libraries.
The British Library Catalogues & Collections:
Explore the British Library catalogues, printed materials, digital collections, and even collection blogs for a wealth of resources.
CIA World Factbook:
As the center of intelligence, the CIA has certainly done its job with The World Factbook, offering information on major reference information around the world. History, people, government, economy, and more are all covered in this online publication.
State Legislative Websites Directory:
Use this database to find information from the legislatures of all 50 U.S. states, DC, and the Territories. You can look up bills, statutes, legislators, and more with this excellent tool.
OpenDOAR:
In the Directory of Open Access Repositories, you can search through freely academic research information with more directly useful resources.
Catalog of U.S. Government Publications:
Search through the Catalog of U.S. Government Publications to find descriptive records for historical and current publications, with direct links where available.

Books & Journals

Instead of heading to the library to bury your face in the stacks, use these search engines to find out which libraries have the books you need, and maybe even find them available online.

WorldCat:
Find items from 10,000 libraries worldwide, with books, DVDs, CDs, and articles up for grabs. You can even find your closest library with WorldCat’s tools.
Google Books:
Supercharge your research by searching this index of the world’s books. You’ll find millions for free and others you can preview to find out if they’re what you’re looking for.
Scirus:
For scientific information only, Scirus is a comprehensive research tool with more than 460 million scientific items including journal content, courseware, patents, educational websites, and more.
HighBeam Research:
Research articles and published sources with HighBeam Research’s tools. You’ll not only be able to search for what you’re looking for, you can also choose from featured research topics and articles. Note: HighBeam is a paid service.
Vadlo:
Vadlo is a life sciences search engine offering protocols, tools, and powerpoints for scientific research and discovery. Find what you’re looking for, and then stick around to check out the forums.
Open Library:
Find the world’s classic literature, open e-books, and other excellent open and free resources in the Open Library. You can even contribute to the library with information, corrections to the catalog, and curated lists.
Online Journals Search Engine:
In this free, powerful scientific search engine, you can discover journals, articles, research reports, and books in scientific publications.
Google Scholar:
Check out Google Scholar to find only scholarly resources on Google. The search specializes in articles, patents, and legal documents, and even has a resource for gathering your citations.
Bioline International:
Search Bioline International to get connected with a variety of scientific journals. The search is managed by scientists and librarians as a collaborative initiative between Bioline Toronto and and the Reference Center on Environmental Information. It is a great tool for students enrolled in both science and environmental management classes.
SpringerLink:
Search through SpringerLink for electronic journals, protocols, and books in just about every subject possible. You can also browse publications by collection and content type.
Directory of Open Access Journals:
When you need top-quality journal writings for free, the Directory of Open Access Journals is a great place to check out. You’ll get access to a searchable journal of full-text quality controlled scientific and scholarly journals.
Jurn:
In this curated academic search engine, you’ll get results from over 4,000 free scholarly e-journals in the arts and humanities.

Science

With a focus on science, these academic search engines return all-science, all the time.

SciSeek:
In this science search engine and directory, you’ll find the best of what the science web has to offer. Browse by category, search by keyword, and even add new sites to the listings.
Chem BioFinder:
Register with PerkinElmer to check out the Chem BioFinder and look up information about chemicals, including their properties and reactions.
Biology Browser:
Biology Browser is a great resource for finding research, resources, and information in the field of biology. You can also check out their Zoological Record and BIOSIS Previews.
Athenus:
Athenus is an authority on science and engineering on the Web, sharing a directory and full-featured web search.
SciCentral:
Use SciCentral as your gateway to the best sources in science. This site has a literature search, journals, databases, and other great tools for finding what you need.
Strategian:
Strategian is a great place to find quality information in all fields of science. Featured resources include free full-text books, patents, and reports, as well as full-text journal and magazine articles, plus a special collection of Vintage Biology with important articles and books in biology.
Science.gov:
In this government science portal, you can search more than 50 databases and 2,100 selected websites from 12 federal agencies. This is an incredible resource for millions of pages of U.S. government science information.
CERN Document Server:
This organization for nuclear research serves up a great search and directory for experiments, archives, articles, books, presentations, and so much more within their documents.
Analytical Sciences Digital Library:
Through the Analytical Sciences Digital Library, you’ll find peer-reviewed, web-based educational resources in analytical sciences, featuring a variety of formats for techniques and applications.
WorldWideScience:
Use WorldWideScience.org as a global science gateway, offering excellent search results in the sciences, and even the option to select specific databases and find resources in your own language.

Math & Technology

Keep your results limited to only the best math and technology resources by using these search engines.

MathGuide:
Check out the MathGuide subject gateway to find online information sources in mathematics. The catalog offers not just a search, but a database of high quality Internet resources in math.
ZMATH Online Database:
Zentralblatt MATH’s online database has millions of entries from thousands of serials and journals dating back as far as 1826. Nearly 35,000 items were added in 2012 alone.
Math WebSearch:
This semantic search engine allows users to search with numbers and formulas instead of text.
Current Index to Statistics:
In this bibliographic index, you’ll find publications in statistics, probability, and related fields. There are more than 160 preferred journals, plus selected articles from 1,200 more and 11,000 statistics books to draw from in this search.
Inspec:
This database was made for scientists and engineers by the Institution of Engineering and Technology. You’ll find nearly 13 million abstracts and research literature, primarily in the fields of physics and engineering.
CiteSeerX:
Get searchable access to the Scientific Research Digital Library by using the CiteSeerX website.
The Collection of Computer Science Bibliographies:
Find more than 3 million references to journal articles, conference papers, and technical reports in computer science with this bibliography collection.
Citebase:
Still in experimental demonstration, Citebase Search is a resource for searching abstracts in math, technology, and more.

Social Science

Researchers working in the fields of psychology, anthropology, and related subjects will find great results using these search engines.

Behavioral Brain Science Archive:
Check out this searchable archive to find extensive psychology and brain science articles.
Social Science Research Network:
In this research network, you can find a wide variety of social science research from a number of specialized networks including cognitive science, leadership, management, and social insurance.
Psycline:
Find a journal with Psycline’s journal and article locator, a tool that offers access to more than 2,000 psychology and social science journals online.
Social Sciences Citation Index:
The Thomson Reuters Social Sciences Citation Index is a paid tool, but well worth its cost for the wealth of relevant articles, search tools, and thorough resources available.
Ethnologue:
Search the languages of the world with Ethnologue, offering an encyclopedic reference of all the world’s known living languages. You’ll also be able to find more than 28,000 citations in the Ethnologue’s language research bibliography.
SocioSite:
Use this site from the University of Amsterdam to browse sociological subjects including activism, culture, peace, and racism.
The SocioWeb:
Check out this guide to find all of the sociological resources you’ll need on the internet. The SocioWeb offers links to articles, essays, journals, blogs, and even a marketplace.
WikiArt:
With this custom Google search engine, you can find open access articles about archaeology.
Encyclopedia of Psychology:
Search or browse the Encyclopedia of Psychology to find basic information, and even translations for information about psychology careers, organizations, publications, people, and history.
Anthropology Review Database:
Through this database, you can get access to anthropology reviews, look up publishers, and find resources available for review.
Anthropological Index Online:
This anthropological online search includes both general search of 4,000 periodicals held in The British Museum Anthropology Library as well as Royal Anthropological Institute films.
Political Information:
Political Information is a search engine for politics, policy, and political news with more than 5,000 carefully selected websites for political information.

History

Find awesome resources for history through these search engines that index original documents, sources, and archives.

David Rumsey Historical Map Collection:
Use the LUNA Browser to check out David Rumsey’s Map Collection with more than 30,000 images, searchable by keyword.
Genesis:
Find excellent sources for women’s history with the Genesis dataset and extensive list of web resources.
Fold3:
Get access to historical military records through Fold3, the web’s premier collection of original military records and memorials.
Internet Modern History Sourcebook:
Use the Internet Modern History Sourcebook to find thousands of sources in modern history. Browse and search to find full texts, multimedia, and more.
Library of Anglo-American Culture and History:
Use the history guide from the Library of Anglo-American Culture and History for a subject catalog of recommended websites for historians, with about 11,000 to choose from.
HistoryBuff:
History Buff offers an online newspaper archive, reference library, and even a historical panoramas section in their free primary source material collection.
Digital History:
University of Houston’s Digital History database offers a wealth of links to textbook, primary sources, and educational materials in digital history. The database has multimedia, an interactive timeline, active learning, and resources for teachers.
Internet Ancient History Sourcebook:
The Internet Ancient History Sourcebook is a great place to study human origins, with full text and search on topics including Mesopotamia, Rome, the Hellenistic world, Late Antiquity, and Christian origins.
History and Politics Out Loud:
History and Politics Out Loud offers a searchable archive of important recordings through history, particularly politically significant audio materials.
History Engine:
In this tool for collaborative education and research, students can learn history by researching, writing, and publishing, creating a collection of historical articles in U.S. history that can be searched for here by scholars, teachers, and the general public.
American History Online:
Through American History Online, you can find and use primary sources from historical digital collections.

Business and Economics

Using these search engines, you’ll get access to business publications, journal articles, and more.

BPubs:
Search the Business Publications Search Engine for access to business and trade publications in a tool that offers not just excellent browsing, but a focused search as well.
Virtual Library Labour History:
Maintained by the International Institute of Social History, Amsterdam, this library offers historians excellent content for learning about economics, business, and more.
EconLit:
Visit EconLit to access more than 120 years of economics literature from around the world in an easily searchable format. Find journal articles, books, book reviews, articles, working papers, and dissertations, as well as historic journal articles from 1886 to 1968.
National Bureau of Economic Research:
On this site, you can learn about and find access to great resources in economic research.
Research Papers in Economics:
Find research in economics and related sciences through the RePEc, a volunteer-maintained bibliographic database of working papers, articles, books, and even software components with more than 1.2 million research pieces.
Corporate Information:
Perfect for researching companies, Corporate Information offers an easy way to find corporate financial records.
Inomics:
Economists will enjoy this excellent site for finding economics resources, including jobs, courses, and even conferences.
DailyStocks:
Easily look up stocks with this search engine to monitor the stock market and your portfolio.
EDGAR Search:
The SEC requires certain disclosures that can be helpful to investors, and you can find them all here in this helpful, next-generation system for searching electronic investment documents.

Other Niches

Find even more specialized information in these niche search engines.

PubMed:
From the U.S. National Library of Medicine, PubMed is a great place to find full-text medical journal articles, with more than 19 million available.
Lexis:
Find reliable, authoritative information for legal search with the Lexis site.
Circumpolar Health Bibliographic Database:
Visit this database to find more than 6,300 records relating to human health in the circumpolar region.
Education Resources Information Center:
In the ERIC Collection, you’ll find bibliographic records of education literature, as well as a growing collection of full-text resources.
MedlinePlus:
A service of the U.S. National Library of Medicine, Medline Plus offers a powerful search tool and even a dictionary for finding trusted, carefully chosen health information.
Artcyclopedia:
Search Artcyclopedia to find everything there is to know about fine art, with 160,000 links, 9,000 artists listed, and 2,900 art sites indexed.

Reference

Get connected with great reference material through these search tools.

Merriam-Webster Dictionary and Thesaurus:
Use this online dictionary and thesaurus to quickly find definitions and synonyms.
References.net:
Through References.net, you can get connected with just about every reference tool available, from patents to almanacs.
Quotes.net:
Need the right thing to say? Check out Quotes.net to reference famous words from famous people.
Literary Encyclopedia:
Check out the Literary Encyclopedia to get access to reference materials in literature, history, and culture.