Limpa, S. I., Z. Islam, and M. S. Reza. “Comparative Evaluation of Bromhexine HCl Mucoadhesive Microspheres Prepared by Anionic, Cationic and Nonionic Polymers”. Bangladesh Pharmaceutical Journal, vol. 23, no. 2, July 2020, pp. 117-24, doi:10.3329/bpj.v23i2.48331.