00313nam a2200109 a 450000500170000000800410001704100080005810000230006624500550008926400480014430000110019220260717091917.0260717s2003    ii            000 0 eng d  aeng1 aStallings, William10aNet Work Securely Essentials /cStallings, William 1aNew Delhi :bPearson Education Asia,c2003.  a366 p.