F. G. Martins, J. F. de Andrade, A. C. Pimenta, L. M. Lourenço, J. R. M. Castro, and V. R. Balbo, “Spectrophotometric study of iron oxidation in the iron(II)/thiocyanate/acetone system and some analytical applications”, Eclet. Quim., vol. 30, no. 3, pp. 63–71, Sep. 2005.