APA

University of Pennsylvania, Zon R., . (19691941). Conservation of renewable natural resources: some fundamental aspects of the problem. Port Washington: Kennikat Press.

Chicago

University of Pennsylvania, Zon Raphael, . 19691941. Conservation of renewable natural resources: some fundamental aspects of the problem. Port Washington: Kennikat Press.

Harvard

University of Pennsylvania, Zon R., . (19691941). Conservation of renewable natural resources: some fundamental aspects of the problem. Port Washington: Kennikat Press.

MLA

University of Pennsylvania, Zon Raphael, . Conservation of renewable natural resources: some fundamental aspects of the problem. Port Washington: Kennikat Press. 19691941.