1. 1. Hussain G, Zafar S, Ch A A, Ch Z A, Ahmad M Z. Comparative Study of Peak Expiratory Flow Rate in Cigarette Smokers and Non-Smokers of Lahore District. Annals 2007; 13(4):255-259.
2. 2. Da Costa JL and Goh B K. Peak Expiratory Flow rate in normal adult Chinese in Singapore. Singapore medical journal 1973; 14 (4):511-514.
3. Peak expiratory flow rate and premenstrual symptoms in healthy non-asthmatic women;Chong;Pharmacotherapy,2000
4. 4. Mohammadzadeh I, Gharagozlou M and Fatemi S A. Normal Values of Peak Expiratory Flow Rate in Children from the Town of Babol, Iran. Iran J Allergy Asthma Immunol 2006; 5 (4): 195-198.
5. 5. Prasad R, Verma SK, Agrawal GG and Mathur N. Prediction Model for Peak Expiratory Flow in North Indian Population. Indian J Chest Dis Allied Sci 2006; 48(2): 103-106.