https://www.telecompaper.com/news/deutsche-telekom-eliminates-discount-on-isdn-lines--63426
DEUTSCHE TELEKOM ELIMINATES DISCOUNT ON ISDN LINES - Telecompaper
Deutsche Telekom has announced plans to eliminate the discount it offers to those people signing up for second analogue lines. The move is believed to be part...
deutsche telekomisdn lineseliminatesdiscounttelecompaper
https://www.computerweekly.com/photostory/2240226509/Business-communications-the-state-of-the-market/3/Mobile-makes-its-mark-on-fixed-lines-and-ISDN
Mobile makes its mark on fixed lines and ISDN - Business communications: the state of the market