E. G. Ciapina, A. O. Santini, P. Los Weinert, M. A. Gotardo, H. R. Pezza, and L. Pezza, “Spectrophotometric determination of diclofenac in pharmaceutical preparations assisted by microwave oven”, Eclet. Quim., vol. 30, no. 1, pp. 29–36, Mar. 2005.