Shi, Y., J. Ji, and C. Wang. “Exploring the NT-ProBNP Expression in Premature Infants With Patent Ductus Arteriosus (PDA) by Echocardiography”. Pakistan Journal of Medical Sciences, Vol. 37, no. 6-WIT, Aug. 2021, doi:10.12669/pjms.37.6-WIT.4853.