M. S. Islam and I. Ueda, “Base Catalyzed Intra Molecular Wittig Reaction Between [2-Ethoxy-3-(4-Substituted Phenyl)-2-Propenylidene] Triphenyl Phosphonium Bromides With Bifunctional Carbonyl Compounds”, Dhaka Univ. J. Pharm. Sci, vol. 3, no. 1, Jun. 2007.