Dyfyniad APA
Gardner, D., & Overcott, N. (2006). Fifty common birds of the upper Midwest. University of Iowa Press.
Dyfyniad Arddull Chicago
Gardner, Dana, and Nancy Overcott. Fifty Common Birds of the Upper Midwest. Iowa City: University of Iowa Press, 2006.
Dyfyniad MLA
Gardner, Dana, and Nancy Overcott. Fifty Common Birds of the Upper Midwest. University of Iowa Press, 2006.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.