Clemens, W.A. (2004). Purgatorius (Plesiadapiformes, Primates?, Mammalia), A Paleocene Immigrant into Northeastern Montana: Stratigraphic Occurrences and Incisor Proportions. Bulletin of Carnegie Museum of Natural History36: 3–13; DOI:10.2992/0145-9058(2004)36[3:PPPMAP]2.0.CO;2
Halliday, T.J.D., Upchurch, P. & Goswami, A. (2015). Resolving the relationships of Paleocene placental mammals. Biological Reviews92(1): 521–550; DOI:10.1111/brv.12242
