000 00300nam a2200109Ia 4500
008 230620s9999||||xx |||||||||||||| ||und||
082 _a515.7246
_bN80 KAT
100 _a Kato, Tosio
245 0 _a Perturbation theory for linear operato
_c Kato, Tosio
260 _b Springer Verlog
_c1980
942 _cBK
999 _c1755
_d1755