[1] G. Birkhoff: Lattice Theory. Providence, 1967. MR 0227053 | Zbl 0153.02501

[2] L. Fuchs: Partially Ordered Algebraic Systems. Pergamon Press, Oxford, 1963. MR 0171864 | Zbl 0137.02001

[3] J. Jakubík: Direct decompositions of partially ordered groups. Czechoslov. Math. J. 10 (1960), 231–243.

[4] J. Jakubík: Competetions and closures of cyclically ordered groups. Czechoslov. Math. J. 41 (1991), 160–169. MR 1087637

[5] V. Novák, M. Novotný: Universal cyclically ordered sets. Czechoslovak Math. J. 35 (1985), 158–161. MR 0779343

[6] V. Novák, M. Novotný: On representation of cyclically ordered sets. Czechoslovak Math. J. 39 (1989), 127–132. MR 0983489

[7] S. Swierczkowski: On cyclically ordered groups. Fundam. Math. 47 (1959), 161–166. DOI 10.4064/fm-47-2-161-166 | MR 0110759 | Zbl 0096.01501

[8] S. D. Želeva: On cyclically ordered groups. Sibir. matem. ž. 17 (1976), 1046–1051. (Russian) MR 0422106

[9] S. D. Želeva: Half-homogeneously cyclically ordered groups. Godišnik Visš. Učebn. Zaved. Prilož. Mat. 17 (1981), 123–136. (Russian) MR 0705070

[10] S. D. Želeva: Cyclically and $T$-like ordered groups. Godišojnik Visš. Učebn. Zaved. Prilož. Mat. 17 (1981), 137–149. (Russian) MR 0705071