G. Chiericato Júnior, W. F. de Giovani, L. C. Garla, and V. H. Betarello, “Complexes of lead(II) perchlorate and hexafluorophosphate with aromatic amine N-oxides”, Eclet. Quim., vol. 14, no. 1, pp. 49–56, Dec. 1989.