Foerch, C; Steinmetz, H (2009). "Left-sided traffic directionality may be the safer "rule of the road" for ageing populations". Med Hypotheses. 73 (1): 20–3. doi:10.1016/j.mehy.2009.01.044. PMID19327893.
dot.gov
fhwa.dot.gov
Weingroff, Richard. "On The Right Side of the Road". United States Department of Transportation. สืบค้นเมื่อ 10 January 2014.
faa.gov
airweb.faa.gov
FAR Sec. 91.115[ลิงก์เสีย](c): "When aircraft, or an aircraft and a vessel, are approaching head-on, or nearly so, each shall alter its course to the right to keep well clear."
Foerch, C; Steinmetz, H (2009). "Left-sided traffic directionality may be the safer "rule of the road" for ageing populations". Med Hypotheses. 73 (1): 20–3. doi:10.1016/j.mehy.2009.01.044. PMID19327893.