Dyfyniad APA

Bormann, F. H., & Kellert, S. R. (1991). Ecology, economics, ethics: The broken circle. Yale University Press.

Dyfyniad Arddull Chicago

Bormann, F. Herbert, and Stephen R. Kellert. Ecology, Economics, Ethics: The Broken Circle. New Haven: Yale University Press, 1991.

Dyfyniad MLA

Bormann, F. Herbert, and Stephen R. Kellert. Ecology, Economics, Ethics: The Broken Circle. Yale University Press, 1991.

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