Não informado. (1909). Circular of the Department of Agriculture, Trinidad and Tobago. Circular of the Department of Agriculture.
Chicago-referens (17:e uppl.)Não informado. Circular of the Department of Agriculture, Trinidad and Tobago. Port of Spain: Circular of the Department of Agriculture, 1909.
MLA-referens (8:e uppl.)Não informado. Circular of the Department of Agriculture, Trinidad and Tobago. Circular of the Department of Agriculture, 1909.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.