Giffin, Emily B.; Gabriel, Diane L.; Johnson, Rolf E. (22 January 1988). "A New Pachycephalosaurid Hell Creek Formation of Montana". Journal of Vertebrate Paleontology. Taylor & Francis, Ltd. 7 (4): 398–407. Diakses tanggal 13 November 2020.
plosone.org
Horner J.R. and Goodwin, M.B. (2009). "Extreme cranial ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus." PLoS ONE, 4(10): e7626. Online full textDiarsipkan 2011-05-01 di Wayback Machine.
web.archive.org
Horner J.R. and Goodwin, M.B. (2009). "Extreme cranial ontogeny in the Upper Cretaceous Dinosaur Pachycephalosaurus." PLoS ONE, 4(10): e7626. Online full textDiarsipkan 2011-05-01 di Wayback Machine.