Sciences

Buteo Books - Offers used, new, and rare books about birds and ornithology.
www.buteobooks.com/

David White Books - Antiquarian and interesting out-of-print medical books; specializing in the history of medicine and pharmacy.
www.davidwhitebooks.co.uk/

Gary Wayner - Used, rare and scholarly natural history books with an emphasis on botany.
www.wayner.com/

GeoLibri - Second-hand books in geology and palaeontology.
www.geolibri.com/

Jan Meemelink - Old, rare and second hand books and prints on botany, gardens, horticulture, and agriculture. based at The Hague, Netherlands.
www.meemelink.com

Jonathan Grobe Books - Used and out-of-print scientific, technical and scholarly books.
www.grobebooks.com/

Natural History Books - Rare and hard to find books, especially ornithology and herpetology.
www.naturalhistorybooks.biz/

Old South Books - Specializes in old and rare medical books; based in Memphis, Tennessee, books bought and sold.
www.oldsouthbooks.com/

Ornithology Books and Journals - Out-of-print ornithology books and journals. Some back issues of hard-to-find journals.
ornithologybooks.tripod.com/

Scholarly Books - Specializing in psychology, psychiatry, psychoanalysis, neuroscience and all aspects of the study of the mind and brain. Catalogues issued periodically and upon request in all fields of specialty.
www.scholarlybooks.com/

Stephan P. Wolf Books - Books and other media on carnivorous plants, free booksearches, and a list of books on the subject. Also available in German.
www.angelfire.com/de/cpbooks/

W. Bruce Fye - Old, rare, and out-of-print books in medicine, surgery, and related fields.
www.fyebooks.com/

Wheldon and Wesley Ltd - Natural history books.
www.users.dircon.co.uk/~wheldwes/