ZULFIANA, Uun. Menulis Gratitude Letter Untuk Meningkatkan Happiness Pada Orang Tua Anak Berkebutuhan Khusus (Abk). Happiness: Journal of Psychology and Islamic Science, [S. l.], v. 1, n. 1, p. 23–30, 2017. DOI: 10.30762/happiness.v1i1.325. Disponível em: http://103.134.17.251/happiness/article/view/325. Acesso em: 1 july. 2026.