[1] Z. FROLÍK:
Sums of ultrafilters. Bull. Amer. Math. Soc. 73 (1967), 87-91.
MR 0203676
[2] Z. FROLÍK: Types of ultrafilters. Proc 2nd Prague Symposium on General Topology in 1966, Academia, Praha 1967.
[3] Z. FROLÍK:
Fixed points of maps of $\beta M$. To appear in Bull. Amer. Math. Soc.
MR 0222847
[4] M. KATĚTOV:
A theorem on mappings. Comment. Math. Univ. Carolinae 8 (1967), 431-3.
MR 0229228
[5] W. RUDIN:
Homogeneity problems in the theory of Čech compactifications. Duke Math. J. 23 (1956), 409-419, 633.
MR 0080902 |
Zbl 0073.39602
[6] T. ISIWATA:
A generalization of Rudin a theorem for the homogeneity problem. Sci. Rep. Tokyo Daigaku Sect. A5 (1957), 300-303.
MR 0095463