Casus Causes and solutions to ethnick ethnic wars: a main paper by Kaufmann<ref>[http://www.columbia.edu/itc/sipa/U6800/readings-sm/Kaufmann_PossibleImpossibleSolns.pdf Kaufmann, Chaim. "Possible and impossible solutions to ethnic civil wars." International security 20.4 (1996): 136-175.]‏</ref>