Hartshorn, T. A., & Alexander, J. W. (1988). Economic geography (3rd ed.). Prentice Hall.
Lua i Stíl Chicago (17ú heag.)Hartshorn, Truman A., agus John W. Alexander. Economic Geography. 3rd ed. Englewood Cliffs, N.J. ; New Delhi: Prentice Hall, 1988.
Lua MLA (8ú heag.)Hartshorn, Truman A., agus John W. Alexander. Economic Geography. 3rd ed. Prentice Hall, 1988.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.