E. Bolaños-Rodríguez, S. Gil-Fundora, W. Francisco-Martín, and J. Álvarez-Álvarez, “Determination of the protection behaviour of the coating of mirrors, using the technique of Electrochemical Spectroscopy of Impedance”, Rev. metal., vol. 39, no. 3, pp. 210–214, Jun. 2003.