GINANJAR, Rikip; UTOMO, Ridho. Sim Card Alarm for Android Smartphone. Ultima InfoSys : Jurnal Ilmu Sistem Informasi, [S. l.], v. 7, n. 1, p. 9–15, 2016. DOI: 10.31937/si.v7i1.507. Disponível em: https://ejournals.umn.ac.id/index.php/SI/article/view/507. Acesso em: 13 jul. 2025.