Nordicom have published a brand new book called Teletext in Europe. From the Analog to the Digital Era. The anthology is edited by Hallvard Moe of University of Bergen, and Hilde Van den Bulck of University of Antwerp and it contains peer reviewed chapters by renowned European researchers in the field of teletext.
The publication is available as free pdf here.
Picture: _MG_2979 by possan, licence: CC BY 2.0