Goodman R (1997) The Strengths and Difficulties Questionnaire: A Research Note. Journal of Child Psychology and Psychiatry, 38, 581-586.
Harter, S.& Pike, R.(1984). The Pictorial Scale of Perceived Competence and Social
Acceptance for Young Children. Child Development.55, 1969-1982.
Jambunathan, S.(2000). Gender Comparisons in the Perception of Self-Competence Among Four-Year-Old Children. The Journal of Genetic Psychology, 161(4), 469-477.
Mantzicopoulos, P.(2006). Younger Children’s Changing Self-Concepts: Boys and Girls From Preschool Through Second Grade. The Journal of Genetic Psychology, 167(3), 289-308.