MATSON, D D Prenatal obstruction of the fourth ventricle. [electronic resource] - The American journal of roentgenology, radium therapy, and nuclear medicine Sep 1956 - 499-506 p. digital Publication Type: Journal Article ISSN: 0002-9580 Subjects--Topical Terms: Brain DiseasesCerebral Ventricles--abnormalitiesFetal DiseasesFourth VentricleHumansNervous System Malformations