Dyfyniad APA

Journal of Forestry. Society of American Foresters.

Dyfyniad Arddull Chicago

Journal of Forestry. Society of American Foresters.

Dyfyniad MLA

Journal of Forestry. Society of American Foresters.

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