Aquino, N., V. Granados, and H. Yee-Madeira. “The Einstein Model and the Heat Capacity of Solids under high pressures”. Revista Mexicana De Física, vol. 55, no. 2, Jan. 2009, pp. 125-0, https://rmf.smf.mx/ojs/index.php/rmf/article/view/3668.