Reality check: the cost–effectiveness of removing body checking from youth ice hockey
Sarah Lacny, Deborah A Marshall, Gillian Currie, Nathalie A Kulin, Willem H Meeuwisse, Jian Kang, Carolyn A Emery
British Journal of Sports Medicine Sep 2014, 48 (17) 1299-1305; DOI: 10.1136/bjsports-2014-093493