Dyfyniad APA

Hesse, W. H., & Mc Donald, R. L. (1974). Earth and its environment. Dickenson Publishing Company.

Dyfyniad Arddull Chicago

Hesse, Walter H., and Robert L. Mc Donald. Earth and Its Environment. California: Dickenson Publishing Company, 1974.

Dyfyniad MLA

Hesse, Walter H., and Robert L. Mc Donald. Earth and Its Environment. Dickenson Publishing Company, 1974.

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