Footnote 7 Olewiler, N., "The Value of Natural Capital in Settled Areas of Canada," Ducks Unlimited Canada and the Nature Conservancy of Canada, 2004.
The Value of Natural Capital in Settled Areas of Canada, Canards Illimités Canada et la Société canadienne pour la conservation de la nature. Référence 8 Atakelty, H., V. Adamowicz et P. Boxall.