science.gov
Explains federated searching across government science databases often described as the deep web.
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Published directory entries matching your search.
rosap.ntl.bts.gov
National Transportation Library record for research on discovering and cataloging hidden-web resources.
nationalacademies.org
National Academies chapter explaining deep-web content, discovery limits and information retrieval.
onlinelibrary.london.ac.uk
University guide to finding databases and information that ordinary search engines do not index.
arxiv.org
Research paper on finding and organizing scholarly databases within the academic invisible web.
getty.edu
Explains how metadata and structured access affect discovery of database-backed and deep-web content.
oedb.org
Guide to search tools and databases that surface information outside conventional web indexes.