Searching the invisible web (deep web, hidden web): WebLens search portal Custom Search Locate deepweb resources by adding the word database to a regular search engine query. The terms invisible web, hidden web, and deep web all refer to the same thing: a massive storehouse of online data that regular search engines don't capture. That's because terabytes of information are buried in databases and other research resources. Searchable and accessible online but often ignored by conventional search engines, these resources exist by the thousands. Known in research circles as the deep web, invisible web, or hidden web, this buried content is an estimated 500 times larger than the surface Web, which is estimated at over eight billion pages.
Deep Web Research 2012 Bots, Blogs and News Aggregators ( is a keynote presentation that I have been delivering over the last several years, and much of my information comes from the extensive research that I have completed over the years into the "invisible" or what I like to call the "deep" web. The Deep Web covers somewhere in the vicinity of 1 trillion plus pages of information located through the world wide web in various files and formats that the current search engines on the Internet either cannot find or have difficulty accessing. The current search engines find hundreds of billions of pages at the present time of this writing. List of academic databases and search engines the general list of search engines for all-purpose search engines that can be used for academic purposesbibliographic databases for information about databases giving bibliographic information about finding books and journal articles. Note that "free" or "subscription" can refer both to the availability of the database or of the journal articles included. This has been indicated as precisely as possible in the lists below. See also
OAIster [OCLC - Digital Collection Services] Access to OAIster A freely-accessible site for searching only OAIster records is available at Additionally, OAIster records are fully accessible through WorldCat.org, and will be included in WorldCat.org search results along with records from thousands of libraries worldwide. They will also continue to be available on the OCLC FirstSearch service to Base Package subscribers, providing another valuable access point for this rich database and a complement to other FirstSearch databases. Contributing to OAIster
Working Links To The Deep Web Hidden Wikis Index pages in Wiki-based format. The Hidden Wiki - The original Hidden Wiki (after Matt's), owned by ion. Created January 2009. Database search engine There are several categories of search engine software: Web search or full-text search (example: Lucene), database or structured data search (example: Dieselpoint), and mixed or enterprise search (example: Google Search Appliance). The largest web search engines such as Google and Yahoo! utilize tens or hundreds of thousands of computers to process billions of web pages and return results for thousands of searches per second. High volume of queries and text processing requires the software to run in highly distributed environment with high degree of redundancy.
Internet Search Engines Search Engines Directory Internet search engines are categorized by topic in our searchable directory of general and specialty search engines. Also listed are resources and tools for exploring the deep web, performing advanced research, and for learning about using search engine tools and technology. Find topical search engines by category. Add Site Search Engine Tools & Technology 100 Search Engines For Academic Research Back in 2010, we shared with you 100 awesome search engines and research resources in our post: 100 Time-Saving Search Engines for Serious Scholars. It’s been an incredible resource, but now, it’s time for an update. 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