Peel 6081: Douglas, Clifford Hugh (1879-1952) [info]. The Alberta experiment: An interim survey. London: Eyre & Spottiswoode, 1937. .
Peel 6081: Douglas, Clifford Hugh (1879-1952) [info]. The Alberta experiment: An interim survey. London: Eyre & Spottiswoode, 1937. .