1. Alt, H.W., Caffarelli, L.A.: Existence and regularity for a minimum problem with free boundary. J. Reine Angew. Math. 325, 105–144 (1981)
2. Alvino, A., Lions, P.-L., Trombetti, G.: On optimization problems with prescribed rearrangements. Nonlinear Anal. 13(2), 185–220 (1989)
3. Alvino, A., Trombetti, G.: Sulle migliori costanti di maggiorazione per una classe di equazioni ellittiche degeneri. Ric. Mat. 27, 413–428 (1978)
4. Amato, V., Gentile, A.: On the symmetric rearrangement of the gradient of a Sobolev function. arXiv (2022)
5. Ambrosio, L., Dal Maso, G.: A general chain rule for distributional derivatives. Proc. Amer. Math. Soc. 108(3), 691–702 (1990)