00785pamaa2200229 4500 0000029126 20091014090000.0 0789559587 004.6 SHE 2001 HD30.335 SHE 2001 Shelly Business data communications : introductory concepts and techniques Gary B. Shelly, Thomas J. Cashman and Judy A. Serwatka. Boston: Course Technology, 2001. various pages: col.ill; 29cm. Shelly Cashman series Computer networks Data transmission systems Business -- Data processing Business -- Communication systems Office practice -- Automation Serwatka, Judy A. Cashman, Thomas J.