Laurin, M.; Reisz, R. R. (1996). "The osteology and relationships of Tetraceratops insignis, the oldest known therapsid". Journal of Vertebrate Paleontology. 16 (1): 95–102. Bibcode:1996JVPal..16...95L. doi:10.1080/02724634.1996.10011287.
Laurin, M.; Reisz, R. R. (1996). "The osteology and relationships of Tetraceratops insignis, the oldest known therapsid". Journal of Vertebrate Paleontology. 16 (1): 95–102. Bibcode:1996JVPal..16...95L. doi:10.1080/02724634.1996.10011287.