Cunha, C. & Voerman (2008). "The   Digitalization   of   the   West   European   Party Systems.". In Anttiroiko, Ari-Veikko (Ed.), Electronic  Government:  Concepts, Methdologies, Tools, and Applications (pp. 3819?3837). IGI Global. https://doi.org/10.4018/978-1-59904-947-2