Smits, C. M. M., R. M. P. Ward, and D. G. Larsen. “HELICOPTER OR FIXED-WING AIRCRAFT: A COST-BENEFIT ANALYSIS FOR MOOSE SURVEYS IN YUKON TERRITORY”. Alces: A Journal Devoted to the Biology and Management of Moose, vol. 30, Jan. 1994, pp. 45-50, https://alcesjournal.org/index.php/alces/article/view/933.