Gaya APA

Skinner, B, J., Porter, S, C. (1989). The Dynamic Earth An Introduction To Physical Geology . United States of America: JOHN WILEY &SONS, Inc.

Gaya MLA

Skinner, Brian, J.., Porter, Stephen, C.. "The Dynamic Earth An Introduction To Physical Geology". United States of America: JOHN WILEY &SONS, Inc, 1989. Text.