Vargas, R., W. Aguirre, ., and J. Diosa. “Anomalous Thermal Properties of YBa2Cu3O7 in the 200-250 K Range”. Revista Mexicana De Física, vol. 42, no. 4, Jan. 1995, pp. 628-32, https://rmf.smf.mx/ojs/index.php/rmf/article/view/2601.