Firth, R. J. Viewdata systems : a practical evaluation guide / R. J. Firth - Manchester : NCC Publications, 1982 - 86 p. (ie 114)p. : ill. ; 22 cm. - Office technology in the'80s . Bibliography: p81 ISBN: 0850123704 Subjects--Topical Terms: Videotex (Data transmission system)Viewdata (Data transmission system)