1. He W Sengupta M Velkoff VA et al http://www.census.gov/prod/2006pubs/p23-209.pdf
2. http://www.nhtsa.dot.gov/people/injury/olddrive/safe/
3. http://www-nrd.nhtsa.dot.gov/Pubs/810992.PDF
4. Very old drivers;Brayne;Findings from a population cohort of people aged 84 and over,2000
5. http://www.aaafoundation.org/pdf/LPWorkshopRecommendations.pdf