1.
Hasni D, Warlem N. The Proportion of Non-smokers in Cases of Chronic Obstructive pulmonary Disease in Padang City West Sumatra. ijmsci [Internet]. 2018Nov.30 [cited 2019Oct.22];5(11):4182-4. Available from: https://valleyinternational.net/index.php/ijmsci/article/view/1609