Mansfield, Edward D., Helen V. Milner, and Jon C. Pevehouse. 2008. “Democracy, Veto Players and the Depth of Regional Integration”. World Economy 31 (1). Blackwell Publishing Ltd: 67–96. doi:10.1111/j.1467-9701.2007.01082.x. Reference Link
Mansfield, Edward D., Helen V. Milner, and Jon C. Pevehouse. (2007) 2007. “Vetoing Co-Operation: The Impact of Veto Players on Preferential Trading Arrangements”. British Journal of Political Science 37 (3). Cambridge University Press: 403–432. doi:10.1017/S0007123407000221. Reference Link