Amazo-Parrado, Diana C. “Do the Autonomy of Free Will and the Principle of Legality in State Contracts Create a Paradox?”. Estudios Socio-Jurídicos, vol. 9, no. 2, Mar. 2010, pp. 181-03, https://revistas.urosario.edu.co/index.php/sociojuridicos/article/view/345.