000 00307nam a2200121Ia 4500
008 221001s1970 xx 000 0 eng d
082 _a512.81 JOH
100 _aJohnson, Donovan A.
245 0 _aUnderstanding numeration systems
260 _aLondon
_bJohn Murray
_c1970
300 _a56p.
942 _2ddc
_cBK
999 _c21036
_d21036