00325nam a2200121Ia 4500082002000000100002200020245005700042260003400099300002000133490004000153500000500193700000500198  a515.35bW418.ST  aWeidmann, Joachim  aSpectral theory of ordinary differential operatorsb  aBerlinbSpringer-Verlagc1987  avi, 303p. Index  aLecture notes in Mathematicsv 1258  a  a