Isard, W. (1975). Introduction to regional science. Prentice-Hall.
Dyfyniad Arddull ChicagoIsard, Walter. Introduction to Regional Science. .Englewood Cliffs, N.J: Prentice-Hall, 1975.
Dyfyniad MLAIsard, Walter. Introduction to Regional Science. Prentice-Hall, 1975.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.