AGRICOLA: Agricultural Online Access
The National Agricultural Library houses one of the worlds largest collections devoted to agriculture and related sciences.
You can search for books or articles, which you can then purchase through publishers websites.
AGRIS
The International System for Agricultural Science and Technology is a great tool for researchers in the field of agriculture.
Although it primarily provides bibliographic information, it does provide links to data sources wherever possible,many of which are open access.
Analytical Sciences Digital Library
The Analytical Sciences Digital Library is an incredible resource. It collects, catalogs, links and publishes peer- reviewed,
web-based discovery materials pertinent to innovations in curricular development and supporting technical resources in the
analytical sciences
Archives Hub
Archives Hub allows you to search subjects, finding relevant information stored in various archives around Scotland, England,
and Wales. Be aware that many of these are physical materials only available at certain institutions, but the site does provide
some links to digital content, including images linking to full-resolution display and links to full-text files and PDF files,
when available.
Artcyclopedia
This should be a go-to resource for art majors. You can search for information by artist, artwork, or location. It will then lead
you to relevant articles from museums, newspapers, and other scholarly sources.
arXiv e-print Archive
Run by Cornell University Library, arXiv.org provides open access to over a million e-prints in the fields of physics,
mathematics, computer science, quantitative biology, quantitative finance and statistics.
Astrophysics Data System
The Astrophysics Data System is run by the Smithsonian Astrophysical Observatory under a NASA grant. It offers three bibliographic databases with a total of more than 12.5 million records.
BASE: Bielefeld Academic Search Engine
BASE is operated by the Bielefeld University Library, and it offers over 100 million documents from over 4,000 sources. Sixty percent of its content is open access, and you can filter your search accordingly.
Bioline International
Bioline International is a resource tool that provides access to open access research from developing countries. This is a great resource to find authoritative sources on health, biodiversity, environmental changes, conservation, and international development.
BioMed Central
BioMed Central provides open access research in more than 290 peer-reviewed journals in the fields of biology, clinical medicine, and health.
CancerData
This repository of open access materials related to the study of cancer is run by the Medical Informatics and Knowledge Engineering team of Maastro Clinic in Maastricht, a city in the Netherlands. The research provided includes clinical protocols, publications, and datasets.
Catalog of U.S. Government Publications
The Catalog of U.S. Government Publications (CGP) is a directory of publications from the legislative, executive, and judicial branches of the U.S. government. Here you can browse more than 500,000 records, including direct links to those available online.
CERN Document Server
CERN is the European Organization for Nuclear Research, and their document server connects researchers with more than a million authoritative scientific sources.
CHBD: Circumpolar Health Bibliographic Database
This is an incredibly specific resource, but it's useful nonetheless. The Circumpolar Health Bibliographic Database contains 6,800 records related to human health in the circumpolar region (i.e., the area around one of Earth's poles). Some journals and articles require an access fee.
ChemBioFinder
ChemBioFinder requires registration, but signing up for this free service will give you access to research related to chemistry and biology.
CIA World Factbook
The CIA World Factbook is a great resource for finding facts about every country in the world, including information about countries' history, geography, transportation, and more.
CiteSeerX
CiteSeerX is a computer and information science database. Here you can find links to scholarly articles and journals about related subjects.
CiteULike
CiteULike allows users to find reputable resources in the form of journals and articles. It also acts as an online bibliography manager for organizing references.
CogPrints
CogPrints is an electronic database of self-archived research for which full texts are available. The database includes work in the fields of psychology, neuroscience, linguistics, computer science, philosophy, and biology.
Computer Science Technical Reports
This is a collection of computer science technical reports from the computer science department of Virginia Tech, as well as industrial and governmental research laboratories.
CORE
CORE aims to aggregate all open access research and facilitate unrestricted access to research. It allows users to check more than 66 million open access articles.
Current Index to Statistics
The Current Index to Statistics allows you to search through journals related to the fields of statistics and probability. No subscription fees are charged, but both free and paid articles are returned in searches. In each case, links to where they can be found online are provided along with the citation. CIS is set to be shut down Dec. 31, 2019, so be sure to use this resource while you can!
dblp computer science bibliography
The dblp computer science bibliography is an online reference for major computer science publications. Although it provides access to both full-text articles and those behind a paywall, you can search for only full-text articles.
De Gruyter Open
An imprint of independent academic publisher De Gruyter, De Gruyter Open publishes and indexes open access material, including 435 journals and more than 100 books, in all major academic disciplines.
Digital History
The Digital History website allows you to browse newspaper articles, journals, and general sources for content related to American history.
Digital Library of the Commons Repository
The Digital Library of the Commons allows users to search through thousands of free and open access documents from around the world.
Dryad
Dryad is a digital repository of curated, open access, scientific research. It is run by a not-for-profit membership organization. If you would like to publish your data on Dryad, there is an associated publishing charge.
EBSCOhost American Doctoral Dissertation Database
This index provides access to over 172,000 dissertations from 1902 to the present in a variety of subjects. Full texts are provided when available.
Education Resources Information Center
ERIC, of the Institution of Education Sciences, allows you to search by topics related to education. Links lead to other sites, where you may have to purchase information, but you can search for full-text articles only.
Elsevier Open Access Journals
This is an A--Z directory of open access journals published by Elsevier. Although there is no search function, you can view the titles and descriptions of each journal.
Encyclopedia of Psychology
The Encyclopedia of Psychology links to various resources sorted by subject. You can search by career, environment behavior relationships, organizations, paradigms and theories, people and history, publications, resources, and underlying reductionist machinery.
EThOS
Run by the British Library, EThOS allows you to browse more than 400,000 doctoral theses. Although some full texts are unavailable through EThOS and must be accessed through the institution at which it was published, a PDF is provided whenever a full text is available.
Europe PMC
The Europe PMC provides access to life science articles, books, patents, and clinical guidelines. Although some of the articles are behind a paywall, there are 3.9 million full texts available.
Fold3
Fold3 allows people to search U.S. military records. Though you must pay to do a thorough search of your own ancestry, you can access a fraction of their records to find general info.
Google Books
Google Books is a great way to search subjects, quotes, authors, and literary sources. Often, the full text will not be available, but you can search excerpts of books for your required information.
Google Correlate
Google Correlate is a custom search engine that allows you to search real-world trends and data.
Google Scholar
Google Scholar has been a secret weapon of students for years. Here you can search topics, and it will return relevant, reputable articles, journals, and research. Full texts are sometimes available, while others are behind paywalls on publishers' websites.
HubMed
HubMed is a database of medical journals and articles. The site is simple and straightforward, and it allows you to filter your results to free full texts only.
Inomics
Although primarily a job-search tool, this site also allows you to search for recent articles by subject. Not only can you do your research here, but you can also sign up and customize a newsfeed that will deliver you articles of interest.
iSEEK Education
iSEEK is a search engine specifically crafted for students and teachers. You will find quality content related to various subjects. Searches can be filtered by grade level, location, organization, resource type, and more.
JSTOR: Journal Storage
JSTOR is a very well-known resource, offering access to journals, primary sources, and books in a variety of disciplines. You can register for a free account, but many of the articles are behind a paywall.
JURN
JURN is a search engine that provides you with links to various scholarly websites, articles, and journals that are all available for free.
LexisWeb
Lexis provides a lot of reliably sourced content about law. Some resources can be accessed for free, but for other resources, you must purchase a membership or pay for each piece of content individually.
Library of Anglo- American Culture & History
The Library of Anglo-American Culture & History is a great resource for history buffs. Find what you need through its compilation of journals, newspapers, and databases.
Library of Congress
The U.S. Library of Congress Online Catalog provides access to hundreds of documents in various subjects, including newspapers, audio files, and government documents.
Literary Encyclopedia
The Literary Encyclopedia provides tons of resources on literature, history, and culture. Although you can view the entries without a membership, you do need one to view the articles in their entirety.
MathGuide
MathGuide is a gateway to various scholarly resources in the field of mathematics, allowing you to sort through libraries, archives, journals, open access journals, and more.
MyScienceWork
In addition to allowing you to share your research with others, MyScienceWork provides access to over 60 million articles, 25 million of which are open access.
National Agricultural Library
Run by the U.S. Department of Agriculture, the National Agricultural Library is an incredible tool for research, allowing you to search by subject and view articles on the publisher's website.
National Archives
The National Archives Catalog is a free resource that helps you find historical documents and journals.
National Bureau of Economic Research
The National Bureau of Economic Research has compiled tons of research into an easy-to-use, searchable website. The research is conducted by over 1,400 economics university professors.
National Criminal Justice Reference Service
The National Criminal Justice Reference Service provides articles and other resources focused on criminal justice and drug-related information. It is funded by the U.S. government and provides links to full-text articles whenever possible.
POPLINE
A free resource containing 380,000 records, POPLINE helps you seek resources related to family planning and reproductive health. Although it is free to search, access to articles does require that you pay a membership fee.
Psycline
Psycline allows you to look for psychology and social sciences journals and articles across many databases. Although some articles are behind paywalls, others are open access.
PubChem
PubChem is a unique tool for researchers, allowing you to search by bioassay, compound, or substance.
Pubget
Pubget allows you to browse by paper or journal, offering you the option of viewing the PDFs of free-access articles or buying the PDFs of articles behind a paywall. According to the site, 10,000 new papers are added each day.
PubPsych
PubPsych allows users to search psychology-related resources and directs them to articles and journals. Full texts are available for most articles, but there are some you may have to purchase.
Science.gov
Science.gov offers 200 million pages of authoritative U.S. government science information. Some of the resources need to be purchased through other sites.
ScienceOpen
ScienceOpen is an incredible research and publishing network offering open access content from more than 24,000 journals.
Scientillion
Scientillion is a smart search engine designed specifically to improve the quality and speed of scientific research.
SciTech Connect
The research on SciTech Connect comes from the U.S. Department of Energy and includes research from the 1940s to today. Of this research, over 400,000 articles are available as full-text PDFs.
Social Science Research Network
The Social Science Research Network (SSRN) is a collection of papers from scholars in the social sciences community. The site offers over 700,000 abstracts and over 600,000 full-text papers.
State Legislative Websites Directory
The National Conference of State Legislatures (NCSL) gathers information from throughout the U.S. to help you cite documents such as bills and statutes.
The SocioWeb
The SocioWeb is a search engine that guides users to sociological resources on the Internet, including websites, articles, and journals.
The Collection of Computer Science Bibliographies
The Collection of Computer Science Bibliographies contains more than three million references. Although the site only provides bibliographic information, it includes links to PDFs or full texts on other sites where possible. There is also an option to search on Google for the full article.
University of Oxford Text Archive
This archive is a catalog of electronic literary and linguistic resources. Although many are freely accessible, some texts have restricted access.
VADLO
VADLO is a life sciences search engine that allows you to search for methods, techniques, protocols, and more. Because it is powered by Google, some of the search results lead to resources behind paywalls.
VET-Bib
VET-Bib, of the European Centre for the Development of Vocational Training, contains 80,000 references related to vocational education training. Not all articles are in English, but you can sort by language if needed.
WikiArc
WikiArc is a search tool that allows you to find open access documents related to archaeology.
zbMATH
This is an excellent database for finding documents, authors, and journals related to mathematics. Some of them are freely available, while others require payment.