Rogers, P. C. (2018). Living with a Giant: Five or six species of aspen reach around the entire northern hemisphere between about 30-65° north latitude. They harbor vast amounts of biodiversity. As goes aspen, so goes dependent plants and animals / von Paul D. Rogers. Topos.

Rogers, Paul C. "Living with a Giant: Five or Six Species of Aspen Reach Around the Entire Northern Hemisphere Between About 30-65° North Latitude. They Harbor Vast Amounts of Biodiversity. As Goes Aspen, so Goes Dependent Plants and Animals / Von Paul D. Rogers." Topos 2018.

Rogers, Paul C. "Living with a Giant: Five or Six Species of Aspen Reach Around the Entire Northern Hemisphere Between About 30-65° North Latitude. They Harbor Vast Amounts of Biodiversity. As Goes Aspen, so Goes Dependent Plants and Animals / Von Paul D. Rogers." Topos, 2018.