Não informado. (1917). Journal of the Department of Agriculture. University of Puerto Rico.
Chicago-referens (17:e uppl.)Não informado. Journal of the Department of Agriculture. Rio Piedras, Porto Rico: University of Puerto Rico, 1917.
MLA-referens (8:e uppl.)Não informado. Journal of the Department of Agriculture. University of Puerto Rico, 1917.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.