G. Aktama, Henky Agung Nugroho, and Muhammad David Perdana Putra, “The Effect of the Covid-19 Free Operation Path Protocol on the Incidence of Lung Complications in Postoperative Elective Patients at dr. Moewardi Hospital Surakarta”, Bioscmed, vol. 5, no. 11, pp. 1030-1036, Jun. 2021.