Rustiana, Deden, Ferry Sudarto, and Al Marwan. “VIDEO PROFILE CONTACT CENTER 121 PADA PT. KAI (PERSERO)”. ICIT Journal 4, no. 2 (August 28, 2018): 138-146. Accessed April 25, 2024. https://ejournal.raharja.ac.id/index.php/icit/article/view/88.