00338nam a2200109Ia 4500008004100000082002000041100002200061245005300083260003800136300001300174440004100187251030b        |||||||| |||| 00| 0 eng d  a515.72bF911.ST  aFriedrichs, K. O.  aSpectral theory of operators in Hilbert spaceb/  aNew York:bSpringer-Verlag,c1973  ax, 244p.  aApplied Mathematical Sciences ; v. 9