Scirus
Search engine that fetches only scientific websites.
www.scirus.com/srsapp

CiteSeer
Search engine for computer science and related matters. For all results number of citations are given which allows to estimate the importance of a paper in a given context. Most of the papers are cached and available for direct download as postscript or PDF.
citeseer.ist.psu.edu

SciSeek
Science search engine and directory. Also provides forums, tools and related news.
www.sciseek.com

ISI Highly Cited
A search tool to identify individuals, departments and laboratories that have made fundamental contributions to the advancement of science and technology in recent decades.
isihighlycited.com

Online Journals Search Engine
A multi-search tool that permits queries of a number of scientific journals.
www.ojose.com

Article Sciences
Scientific article search and order engine, a service provided by Institut de l'Information Scientifique et Technique (INIST) of Centre National de la Recherche Scientifique (CNRS), France.
articlesciences.inist.fr

ISpecies
A species search engine from Rod Page of Glasgow University. Search on either the common or Latin name of a species. Results are generated by querying other data sources.
darwin.zoology.gla.ac.uk/~rpage/ispecies

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