Dyfyniad APA

(1976). Environmental economics. Volume 2. Methods. Martinus Nijhoff.

Dyfyniad Arddull Chicago

Environmental Economics. Volume 2. Methods. Leiden: Martinus Nijhoff, 1976.

Dyfyniad MLA

Environmental Economics. Volume 2. Methods. Martinus Nijhoff, 1976.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.