Eftekharinasab К. “Sard’s Theorem for Mappings Between Fréchet Manifolds”. Ukrains’kyi Matematychnyi Zhurnal 62, no. 12 (December 25, 2010): 1634–1641. Accessed May 4, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/2988.