Hansen-Bristow, Katherine J., and Jack D. Ives. “Composition, Form, and Distribution of the Forest-Alpine Tundra Ecotone, Indian Peaks , Colorado, USA”. ERDKUNDE 39, no. 4 (December 31, 1985): 286–295. Accessed December 3, 2024. https://journals-test.ulb.uni-bonn.de/index.php/erdkunde/article/view/2081.