1. BP Statistical Review of World Energy, June (2012).
2. J. J. Conti, P. D. Holtberg, J. A. Beamon, S. A. Napolitano, A. M. Schaal and J.T. Turnure, Annual Energy Outlook 2012, U.S. Energy Information Administration, Washington DC (2012).
3. R. A. Periana, D. J. Taube, E. R. Evitt, D.G. Loffler, P.R. Wentrcek, G. Voss and T. Masuda, Science, 259, 340 (1993).
4. M.A. Culpepper and A. C. Rosenzweig, Crit. Rev. Biochem. Mol., 47, 483 (2012).
5. M. Khoshtinat, N. A. S. Amin and I. Noshadi, World Academy of Science, Eng. & Technol., 38, 354 (2010).