Gresswell,. (1967). Physical geography. Frederick A. Praeger.
Cita Chicago (17th ed.)Gresswell. Physical Geography. New York: Frederick A. Praeger, 1967.
Cita MLA (9th ed.)Gresswell. Physical Geography. Frederick A. Praeger, 1967.
Atenció: Aquestes cites poden no estar 100% correctes.