B. Walikar, A. Pandit, S. M. Rashinkar, M. V. Watwe, and Y. K., “Current research trends comparing percutaneous dilatational tracheostomy and conventional surgical tracheostomy: a systematic review”, Int J Otorhinolaryngol Head Neck Surg, vol. 4, no. 5, pp. 1121–1124, Aug. 2018.