(1938). Circular. University of Arkansas, College of Agriculture : [U.S. Dept. of Agriculture, cooperating].
Chicago-referens (17:e uppl.)Circular. [Little Rock, Ark.]: University of Arkansas, College of Agriculture : [U.S. Dept. of Agriculture, cooperating], 1938.
MLA-referens (8:e uppl.)Circular. University of Arkansas, College of Agriculture : [U.S. Dept. of Agriculture, cooperating], 1938.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.