Dyfyniad APA

Guyol, N. B. (1971). Energy in the perspective of geography. New Jersey: Prentice-Hall, Inc.

Dyfyniad Arddull Chicago

Guyol, Nathanial B. Energy in the Perspective of Geography. New Jersey: Prentice-Hall, Inc, 1971.

Dyfyniad MLA

Guyol, Nathanial B. Energy in the Perspective of Geography. New Jersey: Prentice-Hall, Inc, 1971.

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