Varsi Rospigliosi, E., N. Rosenvald, and M. A. Torres Maldonado. “The Covid-19 Pandemic, Force Majeure and Changed Contractual Circumstances”. Acta Bioethica, vol. 26, no. 1, May 2020, pp. 19-26, https://revistadematematicas.uchile.cl/index.php/AB/article/view/57351.