Berry, B. J., Conkling, E. C., & Ray, D. M. (1987). Economic Geography. Prentice-Hall.
Cita Chicago (17th ed.)Berry, Brian J.L, Edgar C. Conkling, i D. Michael Ray. Economic Geography. Englewood Cliffs: Prentice-Hall, 1987.
Cita MLA (9th ed.)Berry, Brian J.L, et al. Economic Geography. Prentice-Hall, 1987.
Atenció: Aquestes cites poden no estar 100% correctes.