Sattar, Abdul, et al. “DIAGNOSTIC ACCURACY OF CHEST X-RAY IN TRACHEOBRONCHIAL FOREIGN BODY ASPIRATION IN PAEDIATRIC PATIENTS”. Journal of Ayub Medical College Abbottabad, vol. 23, no. 4, Dec. 2011, pp. 103-5, https://jamc.ayubmed.edu.pk/index.php/jamc/article/view/2399.