Hasibuan, I., Supriatmo, M., Faisal, A., Panggabean, G., Daulay, R., Siregar, Z. and Lubis, H. 2016. Peak expiratory flow rate of primary school children in high and low air pollution level areas. Paediatrica Indonesiana. 43, 1 (Sep. 2016), 10-13. DOI:https://doi.org/10.14238/pi43.1.2003.10-13.