@article{ASNSP_1987_4_14_3_403_0,
     author = {Sakaguchi, Shigeru},
     title = {Concavity properties of solutions to some degenerate quasilinear elliptic {Dirichlet} problems},
     journal = {Annali della Scuola Normale Superiore di Pisa - Classe di Scienze},
     pages = {403--421},
     publisher = {Scuola normale superiore},
     volume = {Ser. 4, 14},
     number = {3},
     year = {1987},
     mrnumber = {951227},
     zbl = {0665.35025},
     language = {en},
     url = {http://www.numdam.org/item/ASNSP_1987_4_14_3_403_0/}
}