Song, Qiaozhen, Ying Lu, Jianzhong Shen, and Lihe Wang. 2011. “Regularity Estimates for a Class of Degenerate Elliptic Equations”. ANNALI SCUOLA NORMALE SUPERIORE - CLASSE DI SCIENZE 10 (3):645-67. https://doi.org/10.2422/2036-2145.2011.3.05.