Suhadi, Suhadi, et al. “Model Problem of Participant Card Services System in the Service Office of the Agency of National Health Security Services Province Southeast Sulawesi Indonesia”. International Journal of Sciences: Basic and Applied Research (IJSBAR), vol. 36, no. 8, Dec. 2017, pp. 200-6, https://www.gssrr.org/JournalOfBasicAndApplied/article/view/8456.