B. Shulruf și G. Wang, „Parent Influence on Outcomes for Children: HIPPY as a Cost-Effective Option”, rcis, vol. 34, pp. 7–20, sep. 2011, Data accesării: nov. 07, 2026. Disponibil la: https://www.rcis.ro/journal/article/view/382-parent-influence-on-outcomes-for-children-hippy-as-a-cost