- Atlanta Nursery (Atlanta, Tex.)
- Atlanta Nursery Company.
- Atlantic Agricultural Economics Committee (Canada)
- Atlantic Monthly
- Atlantic Nursery and Small Fruit Farm.
- Atlantic Nursery Co.
- Atlantic Nursery Company Inc.
- Atlantic Nursery Company, Inc.
- Atlantic Oceanographic and Meteorological Laboratories.
- Atlantic Oceanographic Group (Canada)
- Atlantic Oceanographic Laboratories (U.S.)
- Atlantic Ornamental Nurseries (Cologne, N. J.)
- Atlantic Provinces Livestock Committee.
- Atlantic Shore Life Expeditions (1913)
- Atlantic Small Fruit Farm and Nursery.
- Atlas Powder Company.
- Atluri, Janaki Bai
- Atmowidi, Tri
- Atoda, Kenji
- Atramentowicz, Martine
- Atran, Scott
- Atri, N S
- Atristain, Federico,
- Atroch, André Luiz
- Atroshchenko, Margarita
- Atsaeva, Maret M.
- Atsaides, Samuel P.
- Atsatt, Peter R
- Attademo, Andrés M.
- Attal, Stéphane
- Attama Toykemuy, Marcelino,
- Attanayake, A M Achala S
- Attar, Farideh
- Attayde, José Luiz
- Atteke, Christiane
- Attems, Carl August Theodor Michael von, 1868-1952
- Attems, Carl Gr
- Attems, G
- Attenborough, David Sir
- Attencia, Rebeca
- Atterbury, Ruth Rand, 1895-
- Attermeyer, Katrin
- Attewell, P J
- Atteya, Atteya Mostafa
- Atthakor, Wisrutta
- Atthey, Thomas
- Attia, F I
- Attias, Nina
- Attié, Carole
- Attims, Y.
- Attipoe, Prudence Tonator
- Attiq-ur-Rahman.
- Atti-Serafini, L.
- Attix, Lee
- Attle, H G
- Attolini, Fabiano da Silva
- Atton, F. M.
- Attorre, Fabio
- Attumonelli, Michele, 1753-1826
- Atturio, J. M.
- Attwater, H. P. (Henry Philemon), 1854-1931
- Attwood, Deborah K
- Atty, D B
- Atwal, Avtar Singh, 1927-
- Atwater, Caleb, 1778-1867
- Atwater, Emily Paret, 1873-
- Atwater, Helen W. (Helen Woodard), 1876-1947
- Atwater, Joshua.
- Atwater, W. O. (Wilbur Olin), 1844-1907
- Atwell, C. B.
- Atwell, Charles B
- Atwood Brothers Rose Nursery.
- Atwood, A. E.
- Atwood, Alice C. (Alice Cary), 1876-1947
- Atwood, C. E.
- Atwood, C. J.
- Atwood, Charles, 1854-1929
- Atwood, David G
- Atwood, H. L.
- Atwood, Harry.
- Atwood, Howland
- Atwood, John E
- Atwood, John J.
- Atwood, John T
- Atwood, Jonathan L
- Atwood, Joshua P
- Atwood, N. Duane (Nephi Duane)
- Atwood, N. E.
- Atwood, Root & Co.
- Atwood, W. M.
- Atya Fruit Farm.
- Atyeo, Warren T., 1927-2008
- Atz, Ethel Hafter
- Atz, James W.
- Atzet, Thomas.
- Atzingen, Noé von, 1950-
- Au Yeung, Sui Shan.
- Au, David W. K.
- Au, F.
- Au, Kimberlee L
- Au, Whitlow W L
- Aubé, Charles, 1802-1869
- Aubenton, F. d'
- Aubenton, François D'
- Aubert (Firm)
- Aubert de La Chesnaye-Desbois, François-Alexandre, 1699-1784
- Aubert de La Rüe, E. (Edgar), 1901-1991
- Aubert, Alain
- Aubert, Charles Gabriel, 1877-
- Aubert, E. (Ephrem), 1857-
- Aubert, Hermann.
- Aubert, Jacques F. (Jacques François), 1925-
- Aubert, Matthieu
- Aubin, J. M. A. (Joseph Marius Alexis), 1802-
- Aublet, Fusée, 1720-1778
- Aublet, Jean-Baptiste-Christophe Fusée
- Aubrecht, Gerhard
- Aubret, Fabien
- Aubréville, A. (André), 1897-1982
- Aubrey, David
- Aubrey, David G.
- Aubrey, John, 1626-1697
- Aubriet, Claude, 1665-1742
- Aubriot, Xavier
- Aubry, Abraham.
- Aubry, Janine
- Aubry, Jean, fl 1787-1789
- Aubry, Stéphane
- Aubry, Umberto
- Aubry, Yves 1958-
- Auburn Flower Gardens.
- Auburn Grape Nurseries.
- Auburn University. Agricultural Experiment Station.
- Aucher-Éloy, Remi, 1793-1838
- Auchmutty, James.
- Auchter, E. C. (Eugene Curtis), 1889-1952
- Auckland Institute and Museum.
- Auckland Institute and Museum. Conchology Section.
- Auclair, Walter
- Audas, J. W. (James Wales), 1872-1959
- Audebert, J. B. (Jean Baptiste), 1759-1800
- Audelo-Naranjo, Juan Manuel
- Audesirk, G
- Audesirk, Teresa E
- Audet, Daniel J.
- Audet, Serge
- Audibert, Cédric
- Audinet Serville, M. (Jean Guillaume), 1775-1858
- Audino, Lívia Dorneles.
- Audisio, Paolo Aldo 1955-
- Audisio, Tracy Lynn
- Audot, L.-E. (Louis-Eustache), 1783-1870
- Audouin, Jean Victor, 1797-1841
- Audsley, Neil
- Audubon Association of the Pacific.
- Audubon Nurseries.
- Audubon Nursery Co.
- Audubon Nursery.
- Audubon Society of North Carolina.
- Audubon Society of the Pacific.
- Audubon, Florence,
- Audubon, John James, 1785-1851
- Audubon, John Woodhouse, 1812-1862
- Audubon, Lucy Green Bakewell, 1788-1874
- Audubon, Maria R. (Maria Rebecca), 1843-1925
- Audubon, Victor Gifford, 1809-1860
- Audy, Emile
- Audy, J. Ralph.
- Aue, Dirk
- Aued, Anaide W.
- Aued, Betina
- Auel, H.
- Auer, Alois, 1813-1869
- Auer, Harry Anton, 1878-
- Auer, Harry Anton.
- Auer, Sasha A.
- Auerbach, A.
- Auerbach, Ivan Bogdanovich, 1815-1867
- Auerbach, Leopold.
- Auerbach, M.
- Auerbach, Michael.
- Auerbach, Nancy A.
- Auerswald, B
- Auetragul, Anon
- Aufdenkampe, Anthony Keith
- Aufderheide, Arthur C.
- Auffarth, Jana
- Auffenberg, Kurt.
- Auffenberg, Walter, 1928-2004
- Auffet, J. W.
- Aufrère, Georges
- Aufrère, R
- Auge, Harald
- Augé, Marc
- Auge, O.
- Augee, M. L.
- Augé-Laribé, Michel, 1876-
- Augener, H
- Augenfeld, John M
- Auger Rozenberg, Marie Anne
- Auger, Peter J
- Auger, Philippe
- Augert, Dominique
- Aughanbaugh, John E.
- Aughey, Samuel, 1831-1912
- Aughinbaugh, C. E.
- Augier, Augustin, comte.
- Augier, Lucrecia M.
- Augiust, Lou M
- Auglaize County Shorthorn Breeders' Association
- Auglaize Gardens.
- Augsburger, Alberto
- Augspurger, Tom.
- Augsten, Mariana
- August Lindemann (Firm)
- August Rölker & Sons.
- August Schmid (Firm)
- August Vorndran Nursery.
- August, Robert M.
- Augusta Nurseries.
- Augustana College (Rock Island, Ill.). Library.
- Augustana College and Theological Seminary (Rock Island, Ill.)
- Auguste, Renoir J
- Augusteyn, John
- Augustin, Eliane
- Augustin, H.
- Augustin, Sylvie
- Augustin, Willy
- Augustine & Company.
- Augustine Ascending Elm Research Association.
- Augustine, of Hippo, Saint, 354-430
- Augustine, George J
- Augustine, Jomy
- Augustine, K. T.
- Augustine, Lauren
- Augustinos, Antonios
- Augustinus, Benno Andreas
- Augusto, A.
- Augusto, Anderson M.
- Augusto, EM.
- Augusto, Fernanda Gaudio
- Augusto, Solange C.
- Augustson, G. F.
- Augustyn, Teresa.
- Augustynek, Ronald M.,
- Auinger, E. Anton.
- Auinger, Mathias, 1810-1890
- Auke Bay Fisheries Laboratory.
- Aukema, Berend
- Aukema, J. E.