00284nam a2200109 a 450000500170000002000150001708200220003210000200005424500490007426000320012330000190015520251203091724.0  a0070042594  a620.0042,bD, BEA  aBeam, Walter R.  aSystems engineering: Architecture and Design  aNew YorkbMcGraw-Hillc1990  axii,355p, 22cm