In this paper, necessary and sufficient conditions are given for the existence of extended \(5\)-cycle systems of order \(n\) which have \(r\) idempotent elements.
Citation
Michael E.Raines. On the Existence of Extended \(5\)-Cycle Systems Having a Prescribed Number of Idempotent Elements[J], Ars Combinatoria, Volume 064. 129-162. .