1. Charman Susan. A, Charman, William. N. Oral modified release delivery system In: Rathone, Michael. J., (Eds.),modified release drug delivery technology, 10thed. Marcel Dekker, New York, 2003; 1-10.
2. Narasimharao R, Anusha Reddy M, SwethaReddy N, Divyasagar P and Keerthana K. Design and Evaluation of Metformin Hydrochloride Extended Release Tablets by Direct Compression. International Journal of Research in Pharmaceutical and Biomedical Sciences.2011; 2(3):1118-33
3. Collette, J.H., Moreton, R.C.,. Modified release peroral dosage forms In: Michael,E.Aulton’s pharmaceutics the design & manufacture of medicines, 3rdchurchill livingstone Elsevier, china, 2007; 483-498.
4. Umamaheshwari, R.B., Jain, N.K. Controlled & novel drugdelivery system In: Pharmaceutical product development. 1st,CBS publisher & distributors, New Delhi, India, 2005; 419-454.
5. Ding, Xuan., Alani, W.G. Adam., Robinson, R. Joseph. In:Extended release & targeted drug delivery system”, the science & practice of pharmacy 21st,Lippincott Williams &wilking, new Delhi, India, 2007; 939-961.