Vázquez, G., J. Re, es., M. Solís, R. Vázquez-Nava, M. del Castillo-Mussot, ., and Shu Wang. “Wannier Exciton Bound States for Electron and Hole Spatially Separated in Adjacent 2D Quantum Layers”. Revista Mexicana De Física, vol. 46, no. 3, Jan. 2000, pp. 253-7, https://rmf.smf.mx/ojs/index.php/rmf/article/view/2955.