Hashim, Rugayah, and Hashim Ahmad. “Family Environment, Sibling Relationship and Rivalry towards Quality of Life”. Environment-Behaviour Proceedings Journal 1, no. 3 (August 3, 2016): 113-122. Accessed May 10, 2021. https://ebpj.e-iph.co.uk/index.php/EBProceedings/article/view/356.