2008,Patrice McDermott,Who Needs to Know?, ISBN 1598883089:
Some of these information resources are “deep web” or “hidden web” assets, not easily accessible from typical Internet search engines.
2013 July 1,Marin-Castro, Heidy M.; Victor J. Sosa-Sosa, Ivan Lopez-Arevalo, Hugo Jair Escalante-Baldera,“Automatic Classification of Web Databases Using Domain-Dictionaries”, inMachine Learning and Data Mining in Pattern Recognition, Proceedings of the 9th International Conference, page 431:
The classification of such web databases according to their application domain is an important step towards the integration of deep web sources.
2014 January 1,Das, Guatam,“Mining and Analytic of Deep Web Repositories”, inApplied Algorithms, Proceedings of the 1st International Conference, page xvii:
With the proliferation of deep web repositories...hidden behind proprietary web interfaces...efficient ways of exploring contents in such hidden repositories are of increasing importance in a wide variety of applications.