Butterwick; et al. (2002). "Epidemiologic Analysis of Injury in Five Years of Canadian Professional Rodeo". The American Journal of Sports Medicine. 30 (2). www.ajs.sagepub.com: 193–8. doi:10.1177/03635465020300020801. PMID11912087. S2CID29369550. Am J Sports Med
Butterwick; et al. (2002). "Epidemiologic Analysis of Injury in Five Years of Canadian Professional Rodeo". The American Journal of Sports Medicine. 30 (2). www.ajs.sagepub.com: 193–8. doi:10.1177/03635465020300020801. PMID11912087. S2CID29369550. Am J Sports Med
Butterwick; et al. (2002). "Epidemiologic Analysis of Injury in Five Years of Canadian Professional Rodeo". The American Journal of Sports Medicine. 30 (2). www.ajs.sagepub.com: 193–8. doi:10.1177/03635465020300020801. PMID11912087. S2CID29369550. Am J Sports Med