1. Primary pulmonary hypertension;Walcott;Am J Med,1970
2. Primary pulmonary hypertension;Voelkel,1979
3. Primary pulmonary hypertension;Gatewood,1979
4. Primary pulmonary hypertension in India;Abraham;Indian Heart J,1981
5. Primary pulmonary hypertension of unusually long duration;Charters;Br Heart J,1970