Whitehead, Lawrence. “A Difficult Transition to Achieve : The Slow Disappearance of the Government of the Ruling Party in Mexico”. Política y gobierno 3, no. 1 (April 20, 1996): 31–59. Accessed October 13, 2026. http://www.politicaygobierno.cide.edu/index.php/pyg/article/view/557.