Ahmed, C. I., Akhtar, F., & Zameer, M. (2010). MANAGEMENT OF DIFFICULT AIRWAY BY RETROGRADE ENDOTRACHEAL INTUBATION IN CARDIAC SURGERY PATIENT: Difficult Airway & Endotracheal Intubation. Pakistan Armed Forces Medical Journal, 60(3), 498-9. https://www.pafmj.org/PAFMJ/article/view/1869