Neumer, Simon-Peter, Børge Mathiassen, and Ragnhild Bjørknes. “Systematic Review and Classification Of: Zippys Friends (2. Ed.)”. Ungsinn. Journal of Effective Interventions for Children and Adolescents 10, no. 1 (February 9, 2018). Accessed August 16, 2026. https://septentrio.uit.no/index.php/ungsinn/article/view/7593.