CHRISTOPHERSON, R. W., & HOBBS, G. L. (1998). Applied physical geography geosystems in the laboratory.-- Ed.2. Prentice Hall.

CHRISTOPHERSON, Robert W., and Gail Lewis HOBBS. Applied Physical Geography Geosystems in the Laboratory.-- Ed.2. New Jersey: Prentice Hall, 1998.

CHRISTOPHERSON, Robert W., and Gail Lewis HOBBS. Applied Physical Geography Geosystems in the Laboratory.-- Ed.2. Prentice Hall, 1998.