Khan, Shaheen Pervez, et al. “BACTERIOLOGICAL STUDY OF THROAT SWAB IN SCHOOL GOING CHILDREN: PREVALENCE OF S. HAEMOLYT1CUS AND ITS RELATION WITH RHEUMATIC FEVER”. Journal of Ayub Medical College Abbottabad, vol. 2, no. 2’3, July 1989, pp. 6-9, https://www.jamc.ayubmed.edu.pk/index.php/jamc/article/view/4654.