00301nam a2200109 a 450000500170000002000150001708200150003210000240004724500450007126000530011630000220016920251203091825.0  a013200478X  a004.6bmar  aMarkley, Richard W.  aData communications and interoperability  aLoNew DelhionbPrentice-Hall Internationalc1990  axiv,236p.c23 cm.