Dr. Abqari Shaad, Dr. Kamran Mirza M, Dr. Alam Shahzad, Dr. Haseen Azam, Dr. Shamim Gauhar, and Dr. Izhar fazil M., “Transcatheter closure of patent ductus arteriosus in children weighing 5 kg or less: Initial experienc”, Pediatric Rev: int j pediatrics res, vol. 6, no. 5, pp. 246-251, May 2019.