Gaya APA

Ahrens, W, H. (1989). Weed Socience Vol. 37 No. 5 September 1989 . Madison, Wisconsin, AS: Weed science Society of america.

Gaya MLA

Ahrens, Wiliam, H.. "Weed Socience Vol. 37 No. 5 September 1989". Madison, Wisconsin, AS: Weed science Society of america, 1989. Text.