TY - CHAP AU - Esquinas, J. AU - Herrero, Miguel A. A4 - Díaz Díaz, Jesús Ildefonso A4 - Vegas Montaner, José Manuel PY - 1989 SN - 84-7491-278-4 UR - https://hdl.handle.net/20.500.14352/60768 AB - The authors consider the system, defined for t>0, -∞