Madiyono, B., I. Oesman, S. Sastroasmoro, S. Putra, E. Soelaiman, and K. Rachmad. “Patent Ductus Arteriosus Before and After Surgery”. Paediatrica Indonesiana, Vol. 29, no. 3-4, Apr. 1989, pp. 39-51, doi:10.14238/pi29.3-4.1989.39-51.