Não informado. (1978). Agricultural Reviews and Manuals. Science and Education Administration.
Chicago-referens (17:e uppl.)Não informado. Agricultural Reviews and Manuals. Berkeley, Calif: Science and Education Administration, 1978.
MLA-referens (8:e uppl.)Não informado. Agricultural Reviews and Manuals. Science and Education Administration, 1978.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.