000 002680000a22001210004500
245 _aCalculas of several variables
100 _aMarder, L., ed.
260 _aLondon
_bAllen & Unwin
_c1971
300 _a84 p.
080 _a519.3
_bM3
041 _aEN
942 _cBK
999 _c101269
_d101269