Hartshorn, T. A., & Alexander, J. W. (1988). Economic geography (3rd ed.). Prentice Hall.

Hartshorn, Truman A., and John W. Alexander. Economic Geography. 3rd ed. Englewood Cliffs, N.J. ; New Delhi: Prentice Hall, 1988.

Hartshorn, Truman A., and John W. Alexander. Economic Geography. 3rd ed. Prentice Hall, 1988.