“An Analysis of the Light Curve of the ZZ Ceti Star G117-B15A”. Revista Mexicana de Astronomía y Astrofísica 21, no. 1 (January 1, 1990): 365. Accessed December 11, 2025. https://astronomia.unam.mx/journals/rmxaa/article/view/1990rmxaa. 21. 365k.