Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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