TY - JOUR T1 - Concussion in youth ice hockey: It’s time to break the cycle JF - Canadian Medical Association Journal JO - CMAJ SP - 921 LP - 924 DO - 10.1503/cmaj.110282 VL - 183 IS - 8 AU - L. Syd M. Johnson Y1 - 2011/05/17 UR - http://www.cmaj.ca/content/183/8/921.abstract ER -