- 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.
- Phenotype Books - Antiquarian and secondhand books on agriculture, farm livestock, dogs, and horses.
- 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, book search service, and a list of books on the subject. [English, German]
- W. Bruce Fye - Old, rare, and out-of-print books in medicine, surgery, and related fields.
