Setyawan, Aris Budi, et al. “The Efficiency of Requesting Process for Formal Business-Documents in Indonesia: An Implementation of Web Application Base on Secure and Encrypted Sharing Process”. The Asian Journal of Technology Management (AJTM), vol. 7, no. 2, Dec. 2014, pp. 83-92, https://journal.sbm.itb.ac.id/index.php/ajtm/article/view/1197.