[3] JAKUBÍK J.: 
Lexicographic products of partially ordered groupoids. (Russian), Czechoslovak Math. J. 14 (1964), 281-305. 
MR 0167558[4] JAKUBÍK J., PRINGEROVÁ G.: 
Representation of cyclically ordered groups. Časopis Pěst. Mat. 113 (1988), 184-196. 
MR 0949044[5] JAKUBÍK J., PRINGEROVÁ G.: 
Radical classes of cyclically ordered groups. Math Slovaca 38 (1988), 255-268. 
MR 0977904 | 
Zbl 0662.06004[7] RIEGER L.: 
On ordered and cyclically ordered groups I; II; III. (Czech), Věstník Král. České Spol. Nauk (1946; 1947; 1948), 1-31; 1-33; 1-26. 
MR 0020995[8] SWIERCZOWSKI S.: 
On cyclically ordered groups. Fund. Math. 47 (1959), 161  166. 
MR 0110759[9] ZABARINA A. J.: 
On a theory of cyclically ordered groups. (Russian), Mat. Zametki 31 (1982), 3-12. 
MR 0646907[10] ZABARINA A. J.: 
On linear and cyclic orders in a group. (Russian), Sibirsk. Mat. Zh. 26 (1985), 204-207. 
MR 0788349[11] ZABARINA A. J., PESTOV G. G.: 
On a theorem of Swierczkowski. (Russian), Sibirsk. Mat. Zh. 25 (1984), 46-53. 
MR 0754739[12] ZELEVA S. D.: 
On cyclically ordered groups. (Russian), Sibirsk. Mat. Zh. 17 (1976), 1046-1051. 
MR 0422106 | 
Zbl 0362.06022[13] ZELEVA S. D.: 
Half-homogoeosly cyclically ordered groups. (Russian), Godishnik Vyssh. Uchebn. Zaved. Prilozhna Mat. 17 (1981), 123-136. 
MR 0705070[14] ZELEVA S. D.: 
Cyclically and T-like ordered groups. (Russian), Godishnik Vyssh. Uchebn. Zaved. Prilozhna Mat. 17 (1981), 137-149. 
MR 0705071