3Wellman, H. M & Gellman, S. A. Cognitive development: Foundational theories of core domains. Annual Review of Psychology, 1992, 43 : 337-375
4Hendrik M,Koopmanet C. through the eyes of the child-the development of childrens understanding of the causes of illness, Patient Education and Counseling 2004 Dec, 55(3):363-370
5Bibace R, Walsh M E. Development of children's concepts of illness. Pediatrics,1980,66: 912-917
6Eiser C, Siegal M, Patty J. A re-examination of children's conceptions of contagion. Psychology and Health, 1990, 4:159-165
7Kalish, C. Preshoolers' and bodily understanding of mental reactions contamination: What you don't know can hurt you, but cann't sadden.Developmental Psychology, 1997, 33( 1 ) : 79-91
8Springer K. Young children's understanding of a biological basis for parent-off spring relations. Child Development, 1996, (67): 2841-2856
9Ellen Banks. Concepts of Health and Sickness of Preschool and School-aged Children.CHC, WINTER, 1990, (19) , 1:43-48