On the Combinatorial Alphabets of a Language. - Daniel-Claudian Voinescu (J. Autom. Lang. Comb., 2002)

Synchronized Shuffle on Backbones. - Florin Manea; Victor Mitrana; Daniel-Claudian Voinescu (Fundam. Informaticae, 2006)

Two Variants of Synchronized Shuffle on Backbones. - Henning Bordihn; Florin Manea; Victor Mitrana; Daniel-Claudian Voinescu (Discrete Mathematics and Computer Science, 2014)