R. K. Dewi, E. A. Nardina, and W. Wahyuningsih, “EFFECT OF A BREASTFEEDING SUPPORT PACKAGE ON BREASTFEEDING SELF-EFFICACY AMONG POSTPARTUM MOTHERS IN PRIMARY HEALTHCARE: A QUASI-EXPERIMENTAL STUDY”, jck, vol. 3, no. 02, pp. 87-98, Aug. 2026.