000 00297nam a2200121Ia 4500
008 221001s1965 xx 000 0 eng d
082 _a515.35 ELE
100 _aElen, L. W. F.
245 0 _aDifferential equations
260 _aNew York
_bMacmillan
_c1965
300 _aviii, 220p.
942 _2ddc
_cBK
999 _c9183
_d9183