Nazir, H., Syed Mazhar Ali Naqvi, Anam Ahmad, Saba Zartash, Ali Raza Khan and Waqas Aslam 2023. Ultrasound Versus Bronchoscopy Guided Percutaneous Dilatational Tracheostomy: A Comparative Analysis. Pakistan Journal of Medical Research. 61, 4 (Jan. 2023), 173–178.