1. Adcock, R., Collier, D.: Measurement validity: a shared standard for qualitative and quantitative research. Am. Polit. Sci. Rev. 95(3), 529–546 (2001)
2. Adriaansen, M.: Versatile Citizens: Media Reporting, Political Cynicism and Voter Behavior. University of Amsterdam, Amsterdam (2011)
3. Barisione, M.: Valence image and the standardisation of democratic political leadership. Leadership 5(1), 41–60 (2009)
4. Bartels, L.: The impact of candidate traits in American presidential elections. In: King, A. (ed.) Leaders’ Personalities and the Outcomes of Democratic Elections. Oxford University Press, New York (2002)
5. Bass, B.: Stogdill’s Handbook of Leadership: A Survey of Theory and Research. Free Press, New York (1981)