000 00343nam a2200145 a 4500
005 20140412111303.0
008 001120s19uu xx 00 eng d
020 _a0-7172-4589-6
050 _aER
_bOn2 1990
245 _a1, 2, 3.
300 _a1 v. (unp.) ; col. ; ill.
650 _aCounting
650 _aNumber concept
999 _c103518
_d103518