True, A. C. (1928). A history of agricultural extension work in the United States, 1785-1923. U.S. G.P.O..
Citación estilo ChicagoTrue, Alfred Charles. A History of Agricultural Extension Work in the United States, 1785-1923. Washington, D.C.: U.S. G.P.O., 1928.
Cita MLATrue, Alfred Charles. A History of Agricultural Extension Work in the United States, 1785-1923. U.S. G.P.O., 1928.
Warning: These citations may not always be 100% accurate.