Khan, Hidayat Ullah, Muhammad Said, Naseer Ahmad, Habib ur Rehman, Muhammad Saleem, and Niamat Ullah. 2011. “Experience With Remvoal of Foreign Bodies Tracheo-Broncheal Tree With Rigid Bronchoscope”. Journal of Postgraduate Medical Institute 20 (2). https://www.jpmi.org.pk/index.php/jpmi/article/view/1024.