Assessing the reliability and validity of direct observation and traffic camera streams to measure helmet and motorcycle use
Heather N Zaccaro, Emily C Carbone, Nishita Dsouza, Michelle R Xu, Mary C Byrne, John D Kraemer
Injury Prevention Dec 2015, 21 (6) 415-417; DOI: 10.1136/injuryprev-2014-041399