APA

Longwell C. R., Knopf A., . (1947). A textbook of geology. New York: Wiley.

Chicago

Longwell Chester R, Knopf Adolph, . 1947. A textbook of geology. New York: Wiley.

Harvard

Longwell C. R., Knopf A., . (1947). A textbook of geology. New York: Wiley.

MLA

Longwell Chester R, Knopf Adolph, . A textbook of geology. New York: Wiley. 1947.