V. F. da Silva, L. C. de Santa Maria, L. V. Goncalves, M. G. Fonseca, and L. N. Batista, “Study of Biodiesel Production from Sunflower Oil Using Non Usual Basic Polymeric Resin as Catalyst”, J. Technol. Innov. Renew. Energy, vol. 2, no. 2, pp. 130–138, May 2013.