Cita APA (7th ed.)

Poort, J. M. (1976). Historical geology: Interpretations and applications (2d ed.). Burgess.

Cita Chicago (17th ed.)

Poort, John M. Historical Geology: Interpretations and Applications. 2d ed. Minneapolis: Burgess, 1976.

Cita MLA (8th ed.)

Poort, John M. Historical Geology: Interpretations and Applications. 2d ed. Burgess, 1976.