00360nam a2200121Ia 4500082002000000100003400020245004700054260003200101300001500133490005700148500000500205700002800210  a515.35bR611.DE  aRitger, P. D. and Rose, N. J.  aDifferential equations with applicationsb  aNew YorkbMcGraw-Hillc1968  axiv, 545p.  aInternational series in Pure and Applied Mathematics  a  aRose, N. J. ; jt. auth.