P. N. Ayson, J. E. G. Lopez, and E. G. D. Llanes, “Chronic Suppurative Otitis Media: Bacteriology and Drug Sensitivity Patterns at the Quirino Memorial Medical Center (2004-2005): A Preliminary Study”, Philipp J Otolaryngol Head Neck Surg, vol. 21, no. 1-2, pp. 20–23, Nov. 2006.