Hansen, K. (1981). W. Kenneth Hamblin: THE EARTH’S DYNAMIC SYSTEMS: A textbook in physical geology. 2. ed. Minneapolis, Minn. 1978, VIII, 459 s., ill., 28 cm. Instructor’s manual IV, 65 s., $ 17.95. Paperback $ 10.-. Feffer and Simons Education Div. Sussex. Geografisk Tidsskrift, 81. Hentet fra https://tidsskrift.dk/geografisktidsskrift/article/view/45193