G. Bannach, E. Schnitzler, C. B. Melios, and M. Ionashiro, “Synthesis and thermal studies of solid state 2-chloro- benzylidenepyruvic acid and its compounds with sodium, aluminium (III), gallium (III) and indium (III) cations”, Eclet. Quim., vol. 29, no. 1, pp. 31–40, Jun. 2004.