Strata View

Stratum 1
Service Matches: These resources provide links directly to an article via web-based services.
DOI Proxyhttp://dx.doi.orgMore Info
LinkBatonhttp://www.linkbaton.comMore Info
URLNot AvailableMore Info

Stratum 2
Publication matches: These resources provide a link to the publication in which an article was published.
Academic Radiology Info
Ariadne Info
Behavioral and Brain Sciences Info
Cortex Info
D-Libhttp://www.dlib.orgMore Info
Information Society Info
New Journal of Physics Info
Psycoloquy Info

Stratum 3
High Probability Matches: These resources search one or many publications, so providing a wider scope than a unique match.
CiteBasehttp://citebase.eprints.orgMore Info
OAIster Info

Stratum 4
Low Probability Matches: These resources concentrate on certain subject areas, such as Physics or Computer Science, so are less likely to get an exact match, but may return other articles by the same author or on the same topic
Cogprints Info
Organic Eprintshttp://www.orgprints.orgMore Info
ResearchIndex Info
University of Southampton ECS Publications Info
VT CS Tech Reports Info
Wisdom Archive Info
arXivhttp://www.arxiv.orgMore Info

Stratum 5
Wide-Ranging Matches: These resources cover a large variety of subjects. These are not displayed unless you have requested them in your preferences (sensible defaults are chosen otherwise).
Google Info
Google Scholar Info
Scirushttp://www.scirus.comMore Info
Vivisimo Info
Zetoc Info