M. Yousaf, M. Bhatty, S. Baig, M. Nadeem, and Z. Nasreen, “Different Agroresidues Used in Solid Substrate Fermentation for ?-Amylase Production by Bacillus subtilis-239: Agroresidue Fermentation for Amylase Production”, Pakistan Journal of Scientific & Industrial Research, vol. 51, no. 1, pp. 26–30, Feb. 2008.