Azwar, M. K., F. Kirana, A. Kurniawan, S. Handayani, and S. Setiati. “Gastrointestinal Presentation in COVID-19 in Indonesia: A Case Report”. Acta Medica Indonesiana, vol. 52, no. 1, Apr. 2020, p. 63, http://www.actamedindones.org/index.php/ijim/article/view/1428.