Gaya APA

Ketel, D, H. (1996). Weed Science Vol.44 No. 1 January - March 1996 . Madison, Wisconsin, AS: Weed science Society of america.

Gaya MLA

Ketel, David, H.. "Weed Science Vol.44 No. 1 January - March 1996". Madison, Wisconsin, AS: Weed science Society of america, 1996. Text.