000 00300 a2200133 4500
000 nam a22 7a 4500
020 _a9788120346390
100 _aGurudev Singh
110 _aGurudev Singh
245 _aInformation Sources, Services and System
260 _bPHI
264 _bPHI
942 _cBK
999 _c197690
_d197690