GETIS, A., GETIS, J., BJELLAND, M., & FELLMANN, J. D. (2011). Introduction to geography. McGraw-Hill Book Company.

GETIS, Arthur, Judith GETIS, Mark BJELLAND, and Jerome D. FELLMANN. Introduction to Geography. McGraw-Hill Book Company, 2011.

GETIS, Arthur, et al. Introduction to Geography. McGraw-Hill Book Company, 2011.