alemad, fateh addin najm addin. “EXPOSURE TO SECOND-HAND SMOKE AMONG ADOLESCENT IN SECONDARY SCHOOL STUDENTS IN SANA’A, YEMEN”. International Journal of Public Health Research, vol. 7, no. 1, Apr. 2017, pp. 783-90, https://spaj.ukm.my/ijphr/index.php/ijphr/article/view/36.