M. Saha, M. K. Hossain, M. Ashaduzzaman, S. T. A. Islam, M. Galib, and N. Sharif, “Alkylation of Phenol with Olefins in the Presence of Sulphuric Acid”, Bangladesh J. Sci. Ind. Res., vol. 44, no. 1, pp. 131–136, Jun. 2009.