Jahan, S. T., S. M. A. Sadat, M. R. Islam, A. Z. Azam, and J. A. Chowdhury. “Effect of Various Electrolytes on Theophylline Loaded Sodium Alginate Beads Prepared by Ionic Cross Linking Technique”. Dhaka University Journal of Pharmaceutical Sciences, vol. 11, no. 2, Apr. 2013, pp. 181-9, doi:10.3329/dujps.v11i2.14578.