1. Q&A on coronaviruses (COVID-19), World Health Organization (2020), https://www.who.int/emergencies/diseases/novel-coronavirus-2019/qanswers hub/%0Aq-a-detail/q-a-coronaviruses%0A, last accessed 2021/05/15.
2. Ulfa Rahayu: Sebesar Apa Dampak Orang Tanpa Gejala COVID-19 Berpengaruh Terhadap Penularan Wabah?. hellosehat, Jakarta, (2020).
3. B. Lange, D. Li, E. Nehoran, E. Tuzhilina, and M. Lu2: Early Detection of COVID-19 from Cough Sounds, Symptoms, and Context Machine Learning / Signal Processing Sub-Team CS 472. In: Data science and AI for COVID-19, p. 12 (2020).
4. A. K. Nisa, I. G. P. Suta Wijaya, and A. Aranta: EARLY DETECTION OF ASYMPTOMATIC COVID-19 INFECTION WITH ARTIFICIAL NEURAL NETWORK MODEL THROUGH VOICE RECORDING. no. Cdc, p. 12 (2022).
5. M. Tandan, Y. Acharya, S. Pokharel, and M. Timilsina: Discovering symptom patterns of COVID-19 patients using association rule mining. Comput. Biol. Med., vol. 131, no. January, p. 104249 (2021).