[2] E. Čech:
Bodové množiny. (Point sets). Academia Praha, 1966.
MR 0229205
[4] G. Müller:
Lineare und zyklische Ordnung. Praxis Math. 16 (1974), 261 - 269.
MR 0429660
[5] V. Novák:
Cyclically ordered sets. Czech. Math. Journ., 32 (107) (1982), 460-473.
MR 0669787
[6] I. Chajda V. Novák:
On extensions of cyclic orders. Čas. pěst. mat., to appear.
MR 0796561