Bicycling: Farrell, Paul. “Bicycle Helmets Reduce Risk of Serious Head Injury by Nearly 70%, Study Finds.” The Guardian, Guardian News and Media, 22 Sept. 2016, www.theguardian.com/lifeandstyle/2016/sep/22/bicycle-helmets-reduce-risk-of-serious-head-injury-by-nearly-70-study-finds  Skiing: Yanofsky, David. “Do You Remember When the Skiers Wearing Helmets Were the Weird Ones?” Quartz, Quartz, 26 Feb. 2016, qz.com/621502/if-youre-not-wearing-a-helmet-on-the-slopes-youre-the-weird-one/. Snowboarders in Colorado.” Journal of Pediatric Surgery, U.S. National Library of Medicine, Feb. [...]