共 4 条
[1]
BERESTYCKI H, 1993, BOUNDARY VALUE PROBL, P27
[2]
CLEMENT P, 1987, ANN SCUOLA NORM SUP, V14, P97
[3]
Gidas B., 1981, Math Anal Appl, Part A: Advances in Math Suppl Studied, V7, P369
[4]
Protter M.H., 1967, MAXIMUM PRINCIPLE DI