Buteo Books - Offers used, new, and rare books about birds and ornithology.
David White Books - Antiquarian and interesting out-of-print medical books; specializing in the history of medicine and pharmacy.
Gary Wayner - Used, rare and scholarly natural history books with an emphasis on botany.
GeoLibri - Second-hand books in geology and palaeontology.
Jan Meemelink - Old, rare and second hand books and prints on botany, gardens, horticulture, and agriculture. based at The Hague, Netherlands.
Jonathan Grobe Books - Used and out-of-print scientific, technical and scholarly books.
Natural History Books - Rare and hard to find books, especially ornithology and herpetology.
Old South Books - Specializes in old and rare medical books; based in Memphis, Tennessee, books bought and sold.
Ornithology Books and Journals - Out-of-print ornithology books and journals. Some back issues of hard-to-find journals.
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.
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.
W. Bruce Fye - Old, rare, and out-of-print books in medicine, surgery, and related fields.