Purves, W. K., Heller, C. . H., & Orians, G. H. (1992). Life, the science of biology (3rd ed.). Sunderland ; New York: Sinauer Associates : W.H. Freeman.
Dyfyniad Arddull ChicagoPurves, William K., Craig H. Heller, και Gordon H. Orians. Life, the Science of Biology. 3rd ed. Sunderland ; New York: Sinauer Associates : W.H. Freeman, 1992.
Dyfyniad MLAPurves, William K., Craig H. Heller, και Gordon H. Orians. Life, the Science of Biology. 3rd ed. Sunderland ; New York: Sinauer Associates : W.H. Freeman, 1992.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.