1. Efficient conversion of nonmetric information into metric information;Abelson,1970
2. Young driver risk-taking research: Technical report of experimental study;Bragg,1982
3. The variation of car drivers' accident risk with age;Broughton,1988
4. Theory and methods of social measurement;Coombs,1953
5. Coefficient alpha and the internal structure of tests;Cronbach;Psychometrika,1951