file ode/symbolic/rknstabint.shar for interval of stability of Runge-Kutta-Nystrom methods by Paternoster , Cafaro lang Mathematica ref J.Symb. Comp. (1998) 25, 383-394 file ode/symbolic/stabint.tgz for interval of stability of rational approximations by Paternoster , Cafaro lang Mathematica .