Kew Bibliographic Databases (Kew Record, Economic Botany..)
Agricola (National Agricultural Library’s)
ScienceDirect.com (25% of the world’s science, full text and bibliographic inf.)
Botany Libraries (Harvard University Herbaria)
ISI Web of Knowledge (Web of Science)
Scopus (database of research literature and quality web sources)
W3VA (TROPICOS, at the Missouri Botanical Garden) ST Bibliography
Botanicus Digital Library (historic bot. literature, Missouri Botanical Garden Lib.)
Encyclopedias:
Encyclopedia.com (Columbia Encyclopedia)