Dyfyniad APA
Raven, P. H., & Johnson, G. B. (1999). Biology (5th ed.). WCB/McGraw-Hill.
Dyfyniad Arddull Chicago
Raven, Peter H., and George B. Johnson. Biology. 5th ed. Boston: WCB/McGraw-Hill, 1999.
Dyfyniad MLA
Raven, Peter H., and George B. Johnson. Biology. 5th ed. WCB/McGraw-Hill, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.