000 00319nam a2200109Ia 4500
001 83588
008 170722s9999 xx 000 0 und d
100 _aMarsh, L. G.
245 _aApproach to mathematics :
_b A study groups of seven years old children exploring mathematical apparatus /
260 _c1969.
942 _cGEN
999 _c78831
_d78831