Não informado. (1960). Technical communication. Department of Agriculture and Water Supply.
Chicago-referens (17:e uppl.)Não informado. Technical Communication. Pretoria, Africa do Sul: Department of Agriculture and Water Supply, 1960.
MLA-referens (8:e uppl.)Não informado. Technical Communication. Department of Agriculture and Water Supply, 1960.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.