| 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. |
| Wheldon and Wesley Ltd: Natural history books. |
Classical
