Gras-Velazquez, Agueda, e Verdiana Fronza. «Sustainability in Formal Education: Ways to Integrate It Now». IUL Research 1, no. 2 (dicembre 1, 2020): 154–175. Consultato marzo 25, 2023. https://iulresearch.iuline.it/index.php/IUL-RES/article/view/84.