Petersen, J. F., Sack, D. I., & Gabler, R. E. (2012). Physical geography (10th, international ed.). Brooks/Cole, Cengage Learning.
Chicago (17e ed.) BronvermeldingPetersen, James F., Dorothy Irene Sack, en Robert E. Gabler. Physical Geography. 10th, international ed. Australia: Brooks/Cole, Cengage Learning, 2012.
MLA (9e ed.) BronvermeldingPetersen, James F., et al. Physical Geography. 10th, international ed. Brooks/Cole, Cengage Learning, 2012.
Let op: Deze citaties zijn niet altijd 100% accuraat.