Heydari, Seyed Taghi, Kamran B. Lankarani, Mehrdad Vossoughi, Kazem Javanmardi, Yaser Sarikhani, Kourosh Mahjoor, Mojtaba Mahmoodi, Mohammad Khabaz Shirazi, & Maryam Akbari. " The prevalence and effective factors of crash helmet usage among motorcyclists in Iran." Journal of Injury and Violence Research [Online], 8.1 (2016): 1-5. Web. 17 Dec. 2017