Powell, L. S. (1969). Communication and learning. Pitman.
Dyfyniad Arddull ChicagoPowell, Leonard Sutherland. Communication and Learning. London: Pitman, 1969.
Dyfyniad MLAPowell, Leonard Sutherland. Communication and Learning. Pitman, 1969.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.