He, Chengjun, and Gongbao Li. “The Regularity of Weak Solutions to Nonlinear Scalar Field Elliptic Equations Containing p&Q-Laplacians”. Annales Fennici Mathematici 33, no. 2 (August 1, 2008): 337–371. Accessed March 16, 2026. https://afm.journal.fi/article/view/135236.