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Popular Search Engines
Deep web search engines can come and go. These have withstood the test of time.
BASE-Bielefeld Academic Search Engine
BASE is one of the world's most voluminous search engines especially for academic open access web resources. BASE is operated by Bielefeld University Library. BASE discloses web resources of the "Deep Web", which are ignored by commercial search engines or get lost in the vast quantity of hits.
BizNar: Deep Web Business Search
BizNar scans all kinds of resources including periodicals, government resources, news sources, and social networks. BizNar targets a range of specially selected databases and search engines.
CiteSeerx is an evolving scientific literature digital library and search engine that has focused primarily on the literature in computer and information science. CiteSeerx aims to improve the dissemination of scientific literature and to provide improvements in functionality, usability, availability, cost, comprehensiveness, efficiency, and timeliness in the access of scientific and scholarly knowledge.
Data.gov increases the ability of the public to easily find, download, and use datasets that are generated and held by the Federal Government.
DOAJ: Directory of Open Access Journals
Access to full-text articles from online scholarly publications on a variety of subjects. Supports keyword searching and browsing by subject area. DOAJ is maintained by the Lund University in Sweden.
E-Print Network: Energy, Science, and Technology
E-prints are scholarly and professional works electronically produced and shared by researchers with the intent of communicating research findings to colleagues. They may include preprints, reprints, technical reports, conference publications or other means of electronic communication. Preprints, those selectively shared pre-published documents or articles going through the publication process, have long been recognized and utilized by peer groups throughout the scientific community.
Provides free online access to official publications from all three branches of the Federal Government.
Find Sounds: Search the Web for Sounds
Free website for finding sound effects.
Internet Archive (Including the Way Back Machine)
Its purposes include offering permanent access for researchers, historians, scholars, people with disabilities, and the general public to historical collections that exist in digital format.
The Labyrinth provides free, organized access to resources in medieval studies. The Labyrinth’s easy-to-use links provide connections to databases, services, texts, and images around the world. Each user will be able to find an Ariadne’s thread through the maze of information on the Web.
MagPortal.com® is a search engine and directory for finding online magazine articles. It also provides feeds for use on other websites. The site was officially launched on March 28, 2000.
Making of America (Cornell Univ.)
The Cornell University Library Making of America Collection is a digital library of primary sources in American social history from the antebellum period through reconstruction. The collection is particularly strong in the subject areas of education, psychology, American history, sociology, religion, and science and technology. This site provides access to 267 monograph volumes and over 100,000 journal articles with 19th century imprints. The project represents a major collaborative endeavor in preservation and electronic access to historical texts.
MedNar: Deep Web Medical Search
Free search engine utilizes federated search for medical resources. Search results include government sites, medical societies and some commercial databases.
Beginning with research funded in 2016, all NASA-funded authors and co-authors (both civil servant and non-civil servant) will be required to deposit copies of their peer-reviewed scientific publications and associated data into NASA’s publication repository called NASA PubSpace. This EXCLUDES patents, publications that contain material governed by personal privacy, export control, proprietary restrictions, or national security law or regulations.
OAIster is a union catalog of millions of records representing open access resources that was built by harvesting from open access collections worldwide using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). Freely accessible OAIster includes more than 30 million records representing digital resources from more than 1,500 contributors
Sponsored by the US Dept. of Agriculture, Natural Resources Conservation Service, this database covers anything related to plants. Search by common or scientific name of the plant, characteristics, or by region.
Sponsored by the American Institute of Physics (the world's largest publisher of physics journals), Scitation offers all things physics. Journals can be browsed by title, publisher, and subject. Keyword and advanced searching is also available. Most items are open access but some require payment.
Provides a different method of finding materials using Look Ahead which uses auto-completion, or "suggest" methodology to find content across dynamic websites that match its internal lexicon. Start typing a subject, name, or keyword and it suggests. This is useful for finding very current information.
Voice of the Shuttle (VoS)
Sponsored by the English Dept. of the University of California at Santa Barbara, VoS is a dynamic database of online resources on literature, the humanities, and cultural studies. It includes both primary and secondary resources.
World Wide Science
WorldWideScience.org is a global science gateway comprised of national and international scientific databases and portals
WWW Virtual Library
The WWW Virtual Library (VL) is the oldest catalogue of the Web, started by Tim Berners-Lee, the creator of HTML and of the Web itself, in 1991 at CERN in Geneva. Unlike commercial catalogues, it is run by a loose confederation of volunteers, who compile pages of key links for particular areas in which they are expert; even though it isn't the biggest index of the Web, the VL pages are widely recognised as being amongst the highest-quality guides to particular sections of the Web.
View this 5 minute tutorial to learn more.
Web Crawler Limitations
The Deep Web is mostly due to the limitations in web crawler technology; this software cannot access content hidden below the surface. As technology changes, so does the Deep Web.
Read more about the Deep Web at Hacker News.