“First Principle Study Optical Properties of CH3NH3PbI3 and CH3NH3SnI3 for Perovskite Photovoltaics”. Asian Journal of Current Engineering and Maths 4, no. 5 (October 22, 2015): 49–55. Accessed October 5, 2024. http://informaciontechnologica.com/index.php/ajcem/article/view/1233.