00391nam a2200157Ia 45000010005000000080041000050200018000460400013000640820019000771000018000962450071001142600009001853000011001945460007002056500021002128419140324s9999    xx            000 0 und d  a0-13-637133-7  cPK-LaUMT  a 004.62bBLA-O  aBlack, Uyless  aOSI : A model for computer communications standardscBlack, Uyless  c1991  a528 p.  aEN  aComputer network