Dyfyniad APA

Smith, G. A., & Pun, A. (2010). How does earth work?: Physical geology and the process of science (2nd ed.). Pearson Prentice Hall.

Dyfyniad Arddull Chicago

Smith, Gary A., and Aurora Pun. How Does Earth Work?: Physical Geology and the Process of Science. 2nd ed. Upper Saddle River, N.J.: Pearson Prentice Hall, 2010.

Dyfyniad MLA

Smith, Gary A., and Aurora Pun. How Does Earth Work?: Physical Geology and the Process of Science. 2nd ed. Pearson Prentice Hall, 2010.

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