6Hay.D.Prosocial development.Journal of child psychology and psychiatry, 1994,35:29-71
7Melanie Jackson,Marie S.Tisak.Is prosocial behavior a good thing? Developmental changes in children' s evaluations of helping, shariong, cooperating and comforting. British Joumal of Developmental psychology 2001,19:346-367
8Henry Markovits, Joyce F. Benenson, and Donald L. Krame. Children and Adolescents' Internal Models of Food-Sharing Behavior Include Complex Evaluations of Contextual Factors.Child Development, 2003,11(74):1697-1708
9Ugrel-Semon,R.Moral behavior and moral judgement of children.Journal of Abnormal and social psychology, 1952,47:463-476
10Stab, E & Noerenberg. Property rights, deservingress, reciprocity, friendship: The transactional character of children's sharing behavior. Journal of personality and social psychology, 1981,40:271-289