1/2 ItJ

C 133.265 1/2

Videotex 

C 133.265a1/2 

C 133.265b 

Kef-issues videotex. -Videotex~ The Key 

ssues. IIllu@tr.1 -London: Butler Cox 
1980. 52 S. 4 , 
(Videotex Report Series. Report. 1,/2/.)