\bibitem{Agarwal92}     P.~Agarwal, M.E.~Orazem, L.H.~Garcia-Rubio,
                        {\it Measurement Models for Electrochemical Impedance Spectroscopy. 
                        I. Demonstration and Applicability},
                        J. Electrochem. Soc. {\bf 139} (7), 1917, 1992.