AMERICAN HEART ASS.MONOGRAPH nr 53 195,213 Pulmonary stenosis, aortic enosis,ventricular septal defect:clinical course and indirect assessment.Report from the Joint Study on the Natural History of Congenital Heart Defects.Ed.[Alexander S.Nadas.Ass.ed.:R. Curtis Ellison.William H.Weidman. Dallas 1977 The American Heart Ass.,Inc. 4° s. nlb.8,87,il. Circulation, suppl. nr 1 American Heart Ass.Monograph nr 53