1. Alexander JI, Spence AA (1973) Apparent improvement in postoperative lung volume by using the Entonox apparatus. Br J Anaesth 45: 90
2. Alexander JI, Parikh RK, Spence AA (1973) Postoperative analgesic and lung function: A comparison of narcotic analgesic regimes. Br J Anaesth 45: 90
3. Barrell SE, Abbas HM (1978) Monitoring during physiotherapy after open heart surgery. Physiotherapy 64 /9: 272
4. Bartlett RH (1971) Post traumatic pulmonary insufficiency. In: Cooper P Nyphus L (eds) Surgery annual. Appleton-Century Crofts, New York, chap 1
5. Bartlett RH, Brennan ML, Gazzaniga AB, et al (1973) Studies on the pathogenesis and prevention of postoperative pulmonary complications. Surg Gynecol Obstet 137: 925