Arcozzi, Nicola, Fausto Ferrari, and Francescopaolo Montefalcone. “Regularity of the Distance Function to Smooth Hypersurfaces in Some Two-Step Carnot Groups”. Annales Fennici Mathematici 42, no. 1 (February 1, 2017): 339–356. Accessed November 22, 2024. https://afm.journal.fi/article/view/135665.