1. A novel coronavirus from patients with pneumonia in China, 2019;Zhu;N Engl J Med,2020
2. World Health Organization (WHO). Coronavirus disease (COVID-19) Pandemic. https://www.who.int/emergencies/diseases/novel-coronavirus-2019. Published 2020.
3. Istituto Superiore di Sanità (ISS). Integrated Surveillance of COVID-19 in Italy; 2020. https://www.epicentro.iss.it/coronavirus/bollettino/Infografica_28marzo ENG.pdf.
4. Timing of tracheostomy in patients with prolonged endotracheal intubation: a systematic review;Adly;Eur Arch Otorhinolaryngol,2018
5. UK E. Framework for Open Tracheostomy in COVID-19 Patients; 2020.