Firdaus, and Andika Fitriasari. 2020. “Analysis of Age Distance And Attitude of Parents With The Sibling Rivalry in Paud Kasih Ibu Karangrejo VI Wonokromo Surabaya”. PROCEEDING SURABAYA INTERNATIONAL HEALTH CONFERENCE 2019 1 (1):238-43. https://conferences.unusa.ac.id/index.php/SIHC19/article/view/526.