Convex sets in algebras Radim Bělohlávek (2002) Acta Universitatis Palackianae Olomucensis. Facultas Rerum Naturalium. Mathematica
Convex subsets of partial monounary algebras Danica Jakubíková-Studenovská (1988) Czechoslovak Mathematical Journal
Coregularity of endomorphism monoids of unars Jan Chvalina, Květoslava Matoušková (1984) Archivum Mathematicum
Cyclically ordered sets as partial algebras Vítězslav Novák (1996) Mathematica Bohemica A representation of cyclically ordered sets by means of partial semigroups with an additional unary operation is constructed.
Cyclicity in a special class of hypergroups Thomas N. Vougiouklis (1981) Acta Universitatis Carolinae. Mathematica et Physica