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