Dyfyniad APA

Feather, R. M., Snyder, S. L., & T Hesser, D. (1993). Merrill earth science. McGraw-Hill.

Dyfyniad Arddull Chicago

Feather, Ralph M., Susan Leach Snyder, and Dale T Hesser. Merrill Earth Science. New York: McGraw-Hill, 1993.

Dyfyniad MLA

Feather, Ralph M., et al. Merrill Earth Science. McGraw-Hill, 1993.

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