Hukkelberg, S. and Torsheim, T. 2020. Systematic review and classification of: The Incredible Years (IY): Parenting Program for Preschool Children (3-6 years) and School Children (6-12 years) (2. ed.). Ungsinn. Journal of Effective Interventions for Children and Adolescents. 12, 2 (Nov. 2020). DOI:https://doi.org/10.7557/25.7573.