Dyfyniad APA

Gordon, R. L. (1987). World coal: Economics, policies, and prospects. Cambridge University Press.

Dyfyniad Arddull Chicago

Gordon, Richard L. World Coal: Economics, Policies, and Prospects. Cambridge [Cambridgeshire]: Cambridge University Press, 1987.

Dyfyniad MLA

Gordon, Richard L. World Coal: Economics, Policies, and Prospects. Cambridge University Press, 1987.

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