000 00278nam a2200121Ia 4500
008 210311s9999 xx 000 0 und d
040 _crty
100 _aBhatt, B.D and Sharma, S.R
245 0 _aEducational technology
260 _aNew Delhi
300 _a1992
942 _cTU
999 _c268608
_d268608