Alexander, J. (1979). Economic grography (2nd.). Prentice Hall.
Dyfyniad Arddull ChicagoAlexander, J. Economic Grography. 2nd. New Delhi: Prentice Hall, 1979.
Dyfyniad MLAAlexander, J. Economic Grography. 2nd. Prentice Hall, 1979.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.