1. West JB. Respiratory Physiology—The Essentials. 3rd ed. Baltimore: Williams and Wilkins; 1985.
2. Guenter CA, Welch MH. Pulmonary Medicine. 2nd ed. Philadelphia: JB Lippincott; 1982.
3. Fishman AP. Pulmonary Diseases and Disorders. Vol. 1 and 2. New York: McGraw-Hill; 1980.
4. Menendez R, Kelly HW. Pulmonary-function testing in the evaluation of bronchodilator agents. Clin Pharm. 1983;2:120.
5. Gardner RM. Standardization of spirometry: a summary of recommendations from the American Thoracic Society. Ann Intern Med. 1988;108:217.