“UPGRADE SISTEM PENGAJUAN CUTI KARYAWAN BERBASIS PLATFORM PHP FRAMEWORK CODEIGNITER PADA KRAKATAU IT”, J. Insan Unggul, vol. 14, no. 1, hlm. 25–37, Apr 2026, Diakses: 1 Juli 2026. [Daring]. Tersedia pada: https://jurnal-iu.sttikom-iu.ac.id/index.php/01/article/view/191