1. The lung; clinical physiology and pulmonary function tests;Comroe,1962
2. Oxygen therapy for spontaneous pneumothorax;Northfield;Br Med J,1971
3. The quantity and composition of human colonic flatus;Kirk;Gastroenterology,1949
4. Production and excretion of hydrogen gas in man;Levitt;N Engl J Med,1969
5. Volume, composition, and source of intestinal gas;Levitt;Gastroenterology,1970