Levy Leonard W & Roche, J. P. (1967). The American Political Process.
Dyfyniad Arddull ChicagoLevy Leonard W and John P. Roche. The American Political Process. Calcutta, 1967.
Dyfyniad MLALevy Leonard W and John P. Roche. The American Political Process. 1967.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.