Dyfyniad APA

Peterson. The Life Organic. University of Pittsburgh Press.

Dyfyniad Arddull Chicago

Peterson. The Life Organic. University of Pittsburgh Press.

Dyfyniad MLA

Peterson. The Life Organic. University of Pittsburgh Press.

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