Evidence for an in situ early Paleocene rainforest from Castle Rock, ColoradoDOI: info:10.2113/gsrocky.38.1.173v. 38No. 173–100
Ellis, B., Johnson, Kirk R., and Dunn, Regan E. 2003. "Evidence for an in situ early Paleocene rainforest from Castle Rock, Colorado." Rocky Mountain Geology, 38, (1) 73–100. https://doi.org/10.2113/gsrocky.38.1.173.