Ullah, S., M. Ullah, N. Yousaf, S. Ahmad, and Z. A. Khan. “Curative Surgery In the Treatment of Advanced Cancer of the Hypopharynx and Cervical Oesophagus”. Journal of Postgraduate Medical Institute, vol. 5, no. 2, Aug. 2011, https://www.jpmi.org.pk/index.php/jpmi/article/view/404.