Cyclic extensions of the Medvedev ordered groups Michael R. Darnel (1993) Czechoslovak Mathematical Journal
Cyclic homology of groups and the Bass conjecture. Bruno Eckmann (1986) Commentarii mathematici Helvetici
Cyclic presentations of the trivial group. Edjvet, Martin, Hammond, Paul, Thomas, Nathan (2001) Experimental Mathematics
Cyclic subgroup separability of certain HNN extensions. Wong, Peng Choon, Gan, Hui Woan (1999) Bulletin of the Malaysian Mathematical Society. Second Series