Nerve Axon Equations: II Stability at Rest John Evans Indiana University Mathematics Journal 1973 text pdf 10.1512/iumj.1973.22.22009 10.1512/iumj.1973.22.22009 en Indiana Univ. Math. J. 22 (1973) 75 - 90 state-of-the-art mathematics http://iumj.org/access/