@book{1527,
	author = {Du Plooy, W. J.},
	title = {Die Didaktiese kontinuum /},
	editor = {Universiteit van Suid-Afrika)},
	publisher = {W.J. du Plooy,},
	year = {c1990},
	address = {Pretoria :},
	note = {Intreerede - Unisa, 1990.}
}