Gaya APA

Lutgens, F, K., Tarbuck, I, E, J. (2011). Essentials of Geology . PIE (PS), 2011: PIE (PS), 2011.

Gaya MLA

Lutgens, Frederick, K.., Tarbuck, I., Edward, J.. "Essentials of Geology". PIE (PS), 2011: PIE (PS), 2011, 2011. .