00421nam a2200157Ia 450000500170000002000180001704000090003508200260004410000200007024500530009025000120014326000480015530000190020352100190022265000220024120190420111627.0  a9788120338111  cAEF.  21st ed.a005.43bCHO.  al Choudhury, P.10aOperating System Concepts - Princples and Design  a1st ed.  aNew Delhi :bPhl learning Pvt., Ltd.c2009.  a640p. :c24cm.  aInclude index.  aOperating system.