References
- Kohlberg , L. , Boyd , D. and Levine , C. 1990 . “ The return of stage six: its principle and moral point of view ” . In The Moral Domain , Edited by: Wren , T. 151 – 181 . Cambridge, MA : MIT Press .
- Lickona , T. 1976 . Moral Development and Behavior: Theory, Research, and Social Issues , New York : Holt, Rinehart and Winston .