共 7 条
[1]
BECKERT H, 1971, MATH NACHR, V49, P311
[2]
DO C, 1975, CR ACAD SCI A MATH, V280, P45
[3]
Frehse J, 1971, ABH MATH SEM HAMBURG, V36, P140, DOI 10.1007/BF02995917
[4]
Link H., 1954, ING ARCH, V22, P237