- Amarasinghe, A. A. Thasun
- Amarasinghe, Chamara
- Amaratunga, K L D
- Amardi, Yunico
- Amarilla, Luis Alberto
- Amaro dos Santos, Glauco
- Amaro, Ahyran
- Amaro, Priscila
- Amaro-Espejo, Isabel Araceli
- Amarrillo-Suárez, Ángela
- Amarylis Gardens,
- Amaryllis Gardens.
- Amason, Carl
- Amat, Aníbal G.
- Amat, Eduardo
- Amat, Graciela
- Amatangelo, Kathryn
- Amateur Entomologists' Society (Great Britain)
- Amateur florist.
- Amat-García, Germán
- Amat-Herbozo, Carolina de.
- Amati, B
- Amati, Pasquale, 1726-1796
- Amato de Moraes Vazzoler, Anna Emilia
- Amato, Lusitano, 1511-1568
- Amato, George
- Amato, José Felipe Ribeiro
- Amato, Suzana Bencke
- Amatus Lusitanus
- Amatya, S M
- Amawalk Nursery.
- Amax Petroleum of Canada Inc.
- Amaya, José Antonio
- Amaya, Vanessa
- Amaya-Bulla Diana
- Amaya-Chávez, Araceli
- Amaya-Márquez, Marisol
- Ambacher, Alan H.
- Ambalaparambil, Sudhikumar
- Ambarle, Marke
- Ambarlı, Didem
- Ambauen, Andrew Joseph, 1847-
- Ambedkar, V C
- Ambedkar, Vijaykumar C
- Amber Lake Nurseries.
- Amberger, G
- Amberson, William R
- Amblard, Louis, 1830-1909
- Ambler Nurseries.
- Ambler, Joseph Alfred, 1889-
- Ambler, Joseph Alfred, 1889-1948
- Ambler, Mark.
- Ambler, R. P. (Russel P.)
- Ambo-Rappe, Rohani
- Ambríz García, Demetrio Alonso
- Ambriz, Enrique
- Ambrogi, A Occhipinti
- Ambrogi, Anna Occhipinti
- Ambrosano, Gláucia Maria Bovi
- Ambrose Bros.
- Ambrose, D P
- Ambrose, Dunston P
- Ambrose, G J
- Ambrose, Graeme
- Ambrose, Harrison W
- Ambrose, John D.
- Ambrose, R F
- Ambrose, Rf
- Ambrose, Richard E.
- Ambrose, Richard F
- Ambrose, Robert E.
- Ambrose, Stanley H
- Ambrose, T
- Ambrosi, Francesco, 1821-1897
- Ambrosini, Bartolommeo, 1588-1657
- Ambrosini, Giacinto
- Ambrósio, Ângela Maria
- Ambrósio, Carlos Eduardo
- Ambrósio, Daniela L.
- Ambrosio, Elia
- Ambrósio, Sandra Tereza
- Ambrosio-Calderón, José Dolores
- Ambroson'S,
- Ambrožič, Špela
- Ambrózy, István, Baron.
- Amburgey, Staci
- Amdan, Laura
- Amdrup, Georg Carl, 1866-
- Amdur, Ben H
- Amdur, M A
- Amec Foster Wheeler (Firm)
- Amed, Kalilúdin, active 1879-
- Amedegnato, Christiane
- Amedy, Bro Matthew
- Amegee, Emmanuel Yawo
- Ameghino, Carlos
- Ameghino, Florentino, 1853-1911
- Amein, Michael, 1926-
- Ameixa, Olga
- Ameka, Gabriel
- Amela García, María Teresa
- Amélio, Leandro de Almeida
- Ameloot, Nele
- Amelot de Chaillou, Antoine-Jean, 1732-1795
- Amemiya, S
- Amemiya, Shonan
- Amen, Rahma
- Amend, B. R.
- Amend, R. B.
- Ament, J. G.
- Ament-Velásquez, S. Lorena
- Ameri, Ali
- American Aberdeen-Angus Breeders' Association,
- American Academy of Arts and Sciences.
- American Agricultural Association.
- American Amaryllis Society
- American Antiquarian Society.
- American Apple Congress.
- American Arachnological Society
- American Art Association.
- American Assembly.
- American Association for Study and Prevention of Infant Mortality.
- American Association for the Advancement of Science.
- American Association for the Advancement of Science. Botanical Club.
- American Association for the Advancement of Science. Pacific Coast Committee.
- American Association for the Advancement of Science. Section on Dentistry.
- American Association for the Advancement of Science. Section on Geology and Geography.
- American Association for the Advancement of Science. Section on Medical Sciences.
- American Association for the Advancement of Science. Section on Zoological Sciences.
- American Association for the Advancement of Science. Meeting 1896 : Buffalo, N.Y.)
- American Association for the Advancement of Science. Section on Anthropology.
- American association for the planting and preservation of city trees.
- American Association of Anatomists.
- American Association of Economic Entomologists
- American Association of Immunologists
- American association of medical milk commissions.
- American Association of Medical Superintendents of Asylums for the Insane.
- American Association of Museums.
- American Association of Nurserymen.
- American Association of Nurserymen. Annual Convention Detroit, Mich.) 1915-
- American Association of Park Superintendents.
- American Association of State Highway Officials.
- American Association of Veterinary Laboratory Diagnosticians.
- American Association of Zoo Keepers
- American Association of Zoo Keepers. San Diego Chapter.
- American Berkshire Association.
- American Bird Conservancy.
- American Birding Association.
- American Bison Society.
- American Book Co.
- American Breeders Association.
- American Bryological and Lichenological Society
- American Bryological Society
- American Buff Wyandotte Club.
- American Bulb Company.
- American Canoe Association.
- American Chemical Specialties Co.
- American Civic Association. Department of Parks and Public Reservations.
- American Civic Association. Dept. of National and State Parks.
- American Colony Stores (Jerusalem, Palestine)
- American Daffodil Society.
- American Dahlia Farms.
- American Dairy Show.
- American Dairymen's Association.
- American Devon Cattle Club.
- American Drug Manufacturers Association.
- American Electric Power Service Corporation.
- American Entomological Institute.
- American Entomological Society.
- American Exotic Nurseries.
- American Express Co.
- American Fat Stock Show.
- American Fern Society.
- American Field Seed Co. (Chicago, Ill.)
- American Field Seed Company.
- American Fish Culturists' Association
- American Fish-Cultural Association
- American Fisheries Society
- American Fisheries Society. Committee on Names of Fishes.
- American Fisheries Society. Montana Chapter.
- American Fisheries Society. Southern Division.
- American Florist Supply Co.
- American Florists Company.
- American Forest Congress Washington, D.C.) 1905-
- American Forestry Association.
- American Forestry Co.
- American Forestry Congress
- American fork & hoe company, Cleveland, O.
- American fur fancier's association.
- American Garden Nursery.
- American Garden Perry'S (Nursery),
- American Genetic Association.
- American Geographical Society
- American Geographical Society of New York.
- American ginseng growers' association.
- American Gloxinia And Gesneriad Society.
- American Gloxinia Society.
- American grain growing company.
- American Guernsey Association.
- American Guernsey Cattle Club.
- American Gutta Percha Company,
- American Hame and Bit Company.
- American Home Economics Association. Meeting Boston, Mass.) 1950-
- American Horse Council.
- American Horse Show.
- American Horticultural Society.
- American Humane Education Society.
- American institute of agriculture, Chicago.
- American Institute of Biological Sciences.
- American Institute of Biological Sciences. Committee on the Handbook of Biological Data.
- American Institute of Electrical Engineers
- American Institute of Park Executives.
- American Institute of the City of New York.
- American Iris Society.
- American Irrigation Federation.
- American Jersey Cattle Club.
- American Joint Committee on Horticultural Nomenclature.
- American Kerry and Dexter Cattle Club.
- American Lumber Congress Chicago) 1919-
- American Malacological Society
- American Malacological Union.
- American Malacological Union. Pacific Div.
- American Malacologists, Inc.
- American Medical Association.
- American Meteorological Society.
- American Meteorological Society. Committee on the Compendium of Meteorology.
- American Microscopical Society
- American Mission Press (Madras, India),
- American molasso meal co., inc., New Orleans.
- American Mosquito Control Association.
- American Museum Congo Expedition 1909-1915
- American Museum Congo Expedition (1909-1915)
- American Museum of Natural History
- American Museum of Natural History Field Book Project 2015-
- American Museum of Natural History. Department of Animal Behavior.
- American Museum of Natural History. Department of Education.
- American Museum of Natural History. Department of Fishes and Aquatic Biology.
- American Museum of Natural History. Department of Herpetology.
- American Museum of Natural History. Department of Insects and Spiders.
- American Museum Of Natural History. Department of Invertebrates.
- American Museum of Natural History. Department of Living Invertebrates.
- American Museum of Natural History. Department of Mammalogy.
- American Museum of Natural History. Department of Mammalogy. Archbold Expeditions Collection.
- American Museum of Natural History. Department of Mammalogy. Field Book Collection.
- American Museum of Natural History. Department of Ornithology.
- American Museum of Natural History. Department of Ornithology. Whitney South Sea Expeditions Collection.
- American Museum of Natural History. Department of Public Education.
- American Museum of Natural History. Department of Public Health.
- American Museum of Natural History. Frick Laboratories.
- American Museum of Natural History. Southwestern Research Station.