サードの定理
Sard, Arthur (1965), “Hausdorff Measure of Critical Images on Banach Manifolds”, American Journal of Mathematics 87 (1): 158–174, doi:10.2307/2373229, JSTOR 2373229, MR0173748, Zbl 0137.42501, https://jstor.org/stable/2373229 and also Sard, Arthur (1965), “Errata to Hausdorff measures of critical images on Banach manifolds”, American Journal of Mathematics 87 (3): 158–174, doi:10.2307/2373229, JSTOR 2373074, MR0180649, Zbl 0137.42501, https://jstor.org/stable/2373074 .
Smale, Stephen (1965), “An Infinite Dimensional Version of Sard's Theorem”, American Journal of Mathematics 87 (4): 861–866, doi:10.2307/2373250, JSTOR 2373250, MR0185604, Zbl 0143.35301, https://jstor.org/stable/2373250 .