The Deep Web is World Wide Web content that is not part of the Surface Web, which is indexed by standard search engines.
SEARCH ENGINES: Whether you're looking for specific science research or business data, these search engines will point you in the right direction.

  1. Turbo10: On Turbo10, you'll be able to search more than 800 deep web search engines at a time.
  2. SurfWax: The SurfWax search engine taps into the deep web and offers search tools for feeds, news, blogs, and more.
  3. ZoomInfo: Get information about corporations and job searchers here.
  4. Internet Archive: Here you'll be able to find movies, music, text, and more, even including sites and pages that no longer exist.
  5. TenKWizard: This business search engine covers Forbes, specific industries, and exchanges.
  6. ZabaSearch: This search engine serves up public records like phone numbers and addresses.
  7. Clusty: Perform your search across a number of engines at once with Clusty.
  8. The Online Books Page: Here you can search for more than 25,000 full-text works.
  9. E-Print: Check out E-Print to find sites and databases for scientists and engineers from one search engine.
  10. Guggenheim Museum: Search for artists through this database.
  11. Kompass: On this search engine, you'll find entries for products, services, and companies.
  12. Smithsonian National Portrait Gallery: Find portraits for more than 80,000 people in this database.
  13. Infoplease: Infoplease offers a search engine that combines reference tools like an encyclopedia, atlas and almanac.
  14. Pipl: Pipl brings together profiles, public records, and documents to serve up relevant information about people.
DATABASES: Tap into these databases to access government information, business data, demographics, and beyond.

  1. GPOAccess: If you're looking for US government information, tap into this tool that searches multiple databases at a time.
  2. MedNets: This database makes medical information easily accessible for healthcare professionals.
  3. The Labyrinth: This database from Georgetown offers resources relating to medieval studies.
  4. Musee du Louvre: Through this arts database, you'll be able to find works at the Louvre, inventory from the Department of Prints and Drawings, American works in France, and works in French museums.
  5. Intute: This searchable database links to thousands of scholarly resources.
  6. CBDNet: Find documents from the US Department of Commerce in this database.
  7. USPTO Patent Full-Text and Image Database: Get full-page patent images with this database.
  8. Free Lunch: Through this database, you can get economic data for free.
  9. Hoover's: On this database, you'll find loads of information on businesses.
  10. NYPL Databases and Indexes Online: With this service from the New York Public Library, you can search multiple databases at once, and even narrow down your databases to a specific type or subject.
  11. USDA Plants: Check out the USDA's plants database to get standardized information about plants the live in the US.
  12. CIA Electronic Reading Room: In this database, you can search for CIA documents that have been declassified.
  13. ThomasNet: This directory specializes in industrial products and processes.
  14. PubMed: This service of the US National Library of Medicine offers millions of citations from journals and articles.
  15. Project Vote Smart: Search this database for information on government officials and candidates.
  16. US Census Bureau International Data Base: This database is full of demographics, world population information, and more.
  17. MedBioWorld: MedBioWorld offers access to journals, specialized databases, and more reference tools for medical students and professionals.
  18. Grants.gov: On this database, you'll get access to government grant opportunities.
  19. Penn World Tables: Find data on purchasing power parity and income for 179 countries over 50 years.
  20. FindLaw: Search for cases, legal news, and more in this database.
  21. LexisNexis: This leader in information has public records, business information, unpublished opinions, and so much more.
  22. The National Archives: The National Archives offers lots of databases and records for research.
  23. Guidestar: Guidestar has lots of information about nonprofits, including fiscal reports.
  24. THOMAS: On the Library of Congress' THOMAS database, you can search Congressional documents like bills, nominations, and voting records.
  25. AAAAgency Search: Find information about advertising agencies with this searchable database.
CATALOGS: If you're looking for something specific, but just don't know where to find it, these catalogs will offer some assistance.

  1. Library of Congress Online Catalog: Using this catalog, you can search for just about every book out there.
  2. Library of Congress Prints and Photographs Online Catalog: Go beyond Google's Image Search to find specific current and historical images with this catalog.
  3. Galaxy of Knowledge: Search the Smithsonian Institution Libraries for digital content, books, images, and more.
  4. OAIster: This catalog harvests digital resources, including text, image, and video.
  5. National Gallery of Art: You can find pieces in the National Gallery of Art's collection with this catalog.
  6. HighWire Press: This catalog has full-text, peer-reviewed content from hundreds of journals.
  7. US Copyright Catalog: In this catalog, you'll be able to search for records of works registered with the US Copyright Office.
  8. Project Gutenberg: This searchable catalog offers nearly 20,000 full text books for free.
  9. ERIC: This catalog has more than 1 million records, many of which have links to full text.
  10. SONIC: The Library of Congress' sound collection has more than 2.5 million audio recordings from both published and unpublished sources.
  11. Internet Public Library: Search the catalog of the Internet Public Library to find the information you need.
  12. Law Library of Congress: Search more than 2 million volumes in this legal collection.
  13. Gateway to Library Catalogs: This gateway offers links to hundreds of university and organizational catalogs.
DIRECTORIES: Get hand-picked links to high quality research sources with these directories.
  1. Complete Planet: This deep web directory will connect you with more than 70,000 databases and search engines.
  2. Librarians' Internet Index: This directory is put together by librarians, offering a searchable, human-reviewed gateway to quality sites in the visible and invisible web.
  3. Bureau of Labor Statistics: In the Bureau of Labor Statistics directory, you'll be able to find information about employment, industries, occupations, and lots more.
  4. American Hospital Directory: Check out this searchable directory to find information on US hospitals.
  5. The National Academies Press: In this directory, you can search for thousands of books and PDFs.
  6. WebLens Search Portal: In this portal, you'll find searchable journals, library gateways, and more.
  7. Country Indicators for Foreign Policy: This directory offers statistical tables for foreign policy.
  8. Economagic: This economic data directory is home to more than 200,000 data files.
  9. Digital Librarian: Another librarian-maintained site, this one features links to both content and databases.
  10. SearchSystems: If you're on the hunt for public records, check out SearchSystems' directory.
SOCIAL MEDIA AND MORE: Social media sites are a great way to find content that's obscure or hasn't quite made it to the search engines yet. Use these tools and more to round out your arsenal.
  1. StumbleUpon: This social media site offers a recommendation system for site discovery.
  2. EndNote: This citation tool allows you to search deep web databases from within the program.
  3. AskERIC: This educator's reference links to resources for teaching, education, libraries, and more.
  4. Digg: Digg users submit content that search engines don't find, and often share links before search engines index them.
  5. The World Factbook: Find country profiles, flags of the world, and other international information in this searchable book.
  6. Del.icio.us: This social bookmarking tool offers searchable tags.

GUIDES: Use these guides to learn how to fine-tune your search on the invisible web.
  1. The Ultimate Guide to the Invisible Web: Learn about the details of the invisible web and get suggestions for finding invisible content with this guide.
  2. How to Search the Invisible Web: This guide provides information about the invisible and links to helpful resources.
  3. How to Search the Invisible Web: This guide discusses using databases to search the invisible web.
  4. The Invisible Web: This article discusses the invisible web and how you can use specific resources to find what you want.