000 00288nam a2200133Ia 4500
100 _aRao, Usha
365 _b150
942 _cBK
654 _a
245 _aEducational technology
260 _aMumbai
_bHimalaya Publishing House
_c1991
082 _a371. 3
300 _c21cm
_a(14),238
999 _c420130
_d420130
041 _aeng