https://www.heise.de/news/Rheinland-Pfalz-Politprojekt-digitales-Buecherregal-spart-Geld-und-Papier-9533500.html
https://web.archive.org/web/20231120095430/https://www.heise.de/news/Rheinland-Pfalz-Politprojekt-digitales-Buecherregal-spart-Geld-und-Papier-9533500.html