1. Change and Continuity in the 1996 and 1998 Elections;Abramson,1999
2. Democracy for Realists: Why Elections Do Not Produce Responsive Government;Achen,2016
3. Adams, James. 2001. Party competition and responsible party government. Ann Arbor, MI: University of Michigan Press.Alcántara Sáez, Manuel. Proyecto de Élites Parlamentarias Latinoamericanas (PELA). University of Salamanca.
4. Party system compactness: measurement and consequences;Alvarez;Polit. Anal.,2004
5. The AmericasBarometer by the Latin American Public Opinion Project (LAPOP), Vanderbilt University, www.LapopSurveys.org.