000 00310nam a22001337a 4500
999 _c4309
_d4309
008 170710b xxu||||| |||| 00| 0 eng d
020 _a817643567
082 _a371.33
100 _aRao, V.K.
245 _aEducational technology
260 _aNew Delhi
_bAPH Pub.
_c2004
300 _a407p. :
942 _2ddc
_cBK