Lewis, Frank, and Marvin McInnis. “The Efficiency of the French Canadian Farmer in the Nineteenth Century.” Journal of Economic History Vol. 40, no. 3 (September 1980): 498–514.

Carlos, Ann M., and Frank D. Lewis. “The Economic History of the Fur Trade: 1670 to 1870.” EH.Net (Economic History Association). Last modified 2001. https://eh.net/encyclopedia/the-economic-history-of-the-fur-trade-1670-to-1870/.