R.  Rahul, Satyarthi, J. K., and Srinivas, D., ?Lanthanum and zinc incorporated hydrotalcites as solid base catalysts for biodiesel and biolubricants production?, Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry, vol. 50, no. 8, pp. 1017-1025, 2011.