Dyfyniad APA

Steinbock. The Fourfold. Northwestern University Press.

Dyfyniad Arddull Chicago

Steinbock. The Fourfold. Northwestern University Press.

Dyfyniad MLA

Steinbock. The Fourfold. Northwestern University Press.

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