NAGLAA M. ALY, M.D.; HEBA A. LABIB AHMED, M.D.; WAEL A. MOHAMED, M.D.; AHMED Y.A. ELBATSH, M.Sc.. "Ultrasound Guided Percutaneous Tracheostomy versus Conventional Tracheostomy: Technique and Outcome". The Medical Journal of Cairo University, 89, September, 2021, 1669-1678. doi: 10.21608/mjcu.2021.194984