Varmazyar, S.; Mortazavi, SB; Arghami, S.; Hajizadeh, E. (2014). "Relationship between organisational safety culture dimensions and crashes". International Journal of Injury Control and Safety Promotion. 23 (1): 72–8. doi:10.1080/17457300.2014.947296. PMID25494102. S2CID26702114.
"625 ILCS 5/12-601.1. Traffic control signal preemption devices.". Illinois Compiled Statutes. Illinois General Assembly. 2 July 2003. Retrieved 2 December 2018.
Varmazyar, S.; Mortazavi, SB; Arghami, S.; Hajizadeh, E. (2014). "Relationship between organisational safety culture dimensions and crashes". International Journal of Injury Control and Safety Promotion. 23 (1): 72–8. doi:10.1080/17457300.2014.947296. PMID25494102. S2CID26702114.
Varmazyar, S.; Mortazavi, SB; Arghami, S.; Hajizadeh, E. (2014). "Relationship between organisational safety culture dimensions and crashes". International Journal of Injury Control and Safety Promotion. 23 (1): 72–8. doi:10.1080/17457300.2014.947296. PMID25494102. S2CID26702114.