00314nam a22001337a 4500003000500000020002300005038001700028082001300045100001600058245004600074250001200120260003700132300001100169NUST  a9780070671201qPB.  aFizza Ishaq   a004bNOR  aNorton, P.   aIntroduction to Computers /cPetor Norton  a7th ed.  aNew Delhi :bMcGrew Hill,c2013.  a622 p.