Ryan, Michael J.; Evans, David C. (2005). "Ornithischian Dinosaurs". In Currie, Phillip J.; Koppelhus, Eva (eds.). Dinosaur Provincial Park: A Spectacular Ancient Ecosystem Revealed. Bloomington: Indiana University Press. pp. 312–348. ISBN978-0-253-34595-0.
Ryan, M.J.; Russell, A.P. (2003). "New centrosaurine ceratopsids from the late Campanian of Alberta and Montana and a review of contemporaneous and regional patterns of centrosaurine evolution". Journal of Vertebrate Paleontology. 23 (3): 91A. doi:10.1080/02724634.2003.10010538. S2CID220410105.
Ryan, M.J.; Russell, A.P. (2005). "A new centrosaurine ceratopsid from the Oldman Formation of Alberta and its implications for centrosaurine taxonomy and systematics". Canadian Journal of Earth Sciences. 42 (7): 1369–1387. Bibcode:2005CaJES..42.1369R. doi:10.1139/e05-029. hdl:1880/47001. S2CID128478038.
Chiba, Kentaro; Ryan, Michael J.; Fanti, Federico; Loewen, Mark A.; Evans, David C. (2018). "New material and systematic re-evaluation of Medusaceratops lokii (Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana)". Journal of Paleontology. 92 (2): 272–288. Bibcode:2018JPal...92..272C. doi:10.1017/jpa.2017.62. S2CID134031275.
Rogers, R. R. (1990). "Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality". PALAIOS. 5 (5): 394–41. Bibcode:1990Palai...5..394R. doi:10.2307/3514834. JSTOR3514834.
Ryan, M.J.; Russell, A.P. (2005). "A new centrosaurine ceratopsid from the Oldman Formation of Alberta and its implications for centrosaurine taxonomy and systematics". Canadian Journal of Earth Sciences. 42 (7): 1369–1387. Bibcode:2005CaJES..42.1369R. doi:10.1139/e05-029. hdl:1880/47001. S2CID128478038.
Ryan, M.J.; Russell, A.P. (2005). "A new centrosaurine ceratopsid from the Oldman Formation of Alberta and its implications for centrosaurine taxonomy and systematics". Canadian Journal of Earth Sciences. 42 (7): 1369–1387. Bibcode:2005CaJES..42.1369R. doi:10.1139/e05-029. hdl:1880/47001. S2CID128478038.
Chiba, Kentaro; Ryan, Michael J.; Fanti, Federico; Loewen, Mark A.; Evans, David C. (2018). "New material and systematic re-evaluation of Medusaceratops lokii (Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana)". Journal of Paleontology. 92 (2): 272–288. Bibcode:2018JPal...92..272C. doi:10.1017/jpa.2017.62. S2CID134031275.
Rogers, R. R. (1990). "Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality". PALAIOS. 5 (5): 394–41. Bibcode:1990Palai...5..394R. doi:10.2307/3514834. JSTOR3514834.
Rogers, R. R. (1990). "Taphonomy of three dinosaur bone beds in the Upper Cretaceous Two Medicine Formation, northwestern Montana: Evidence for drought-related mortality". PALAIOS. 5 (5): 394–41. Bibcode:1990Palai...5..394R. doi:10.2307/3514834. JSTOR3514834.
Ryan, M.J.; Russell, A.P. (2003). "New centrosaurine ceratopsids from the late Campanian of Alberta and Montana and a review of contemporaneous and regional patterns of centrosaurine evolution". Journal of Vertebrate Paleontology. 23 (3): 91A. doi:10.1080/02724634.2003.10010538. S2CID220410105.
Ryan, M.J.; Russell, A.P. (2005). "A new centrosaurine ceratopsid from the Oldman Formation of Alberta and its implications for centrosaurine taxonomy and systematics". Canadian Journal of Earth Sciences. 42 (7): 1369–1387. Bibcode:2005CaJES..42.1369R. doi:10.1139/e05-029. hdl:1880/47001. S2CID128478038.
Chiba, Kentaro; Ryan, Michael J.; Fanti, Federico; Loewen, Mark A.; Evans, David C. (2018). "New material and systematic re-evaluation of Medusaceratops lokii (Dinosauria, Ceratopsidae) from the Judith River Formation (Campanian, Montana)". Journal of Paleontology. 92 (2): 272–288. Bibcode:2018JPal...92..272C. doi:10.1017/jpa.2017.62. S2CID134031275.