共 15 条
- [12] LAETSCH T, 1973, J DIFF EQU, V13, P12
- [13] PARTER SV, 1973, 162 U WISC COMP SCI
- [14] PIMBLEY GH, 1962, J MATH MECH, V11, P121
- [15] Protter Murray H., 1984, MAXIMUM PRINCIPLES D, DOI [10.1007/978-1-4612-5282-5, DOI 10.1007/978-1-4612-5282-5]