Irianto, Komang Agung, and Taufan Adityawardhana. “Effective Perioperative Scoring in Orthopedic Surgery to Prevent Covid-19 Infection”. Universa Medicina 40, no. 2 (July 7, 2021): 96–106. Accessed October 19, 2021. https://univmed.org/ejurnal/index.php/medicina/article/view/1122.