000 002630000a22001210004500
245 _aReal variable
100 _aHyslop, James M.
260 _aLondon
_bOliver & Boyd
_c1960
300 _aviii, 136p.
080 _a517.13
_bH8
041 _aEN
942 _cBK
999 _c111555
_d111555