000 00610nam a2200229Ia 4500
003 OSt
005 20220912153049.0
006 a|||||r|||| 00| 0
007 ta
008 220909b |||||||| |||| 00| 0 eng d
024 _a22848
037 _cTextual
040 _aCSL
_beng
_cCSL
041 _aeng
082 _aB334, L3.1/.2/.3
245 0 _aWave equations classification and characteristics elliptics and parabolic equations
260 _c1973
300 _ap.
_ccm.
650 _aPartial differential equations
942 _hB334, L3.1/.2/.3
_cTEXL
_2CC
999 _c97522
_d97522