000 00331nam a2200145Ia 4500
020 _a9780602575861
082 _b1975
_a510
100 _a"Ruth Merttens and David Kirkby"
245 0 _aAbacus evolve Textbook I
260 _c0
300 _a80
944 _cBK
999 _c554156
_d554156