Template:Pigg et al., 2021
- Pigg, K.B.; DeVore, M.L.; Greenwood, D.R.; Sundue, M.A.; Schwartsburd, P.; Basinger, J.F. 2021. Fossil Dennstaedtiaceae and Hymenophyllaceae from the Early Eocene of the Pacific Northwest. International Journal of Plant Sciences 182(9): 793–807. doi:10.1086/715633.