Παραπομπή APA

Spencer, E. W. (1969). Introduction to the structure of the earth. McGraw-Hill.

Παραπομπή Chicago Style

Spencer, Edgar W. Introduction to the Structure of the Earth. New York: McGraw-Hill, 1969.

Παραπομπή MLA

Spencer, Edgar W. Introduction to the Structure of the Earth. McGraw-Hill, 1969.