Homomorphic Characterizations of Indexed Languages. - Séverine Fratani; El Makki Voundy (LATA, 2016)

Langages epsilon-sûrs et caractérisations des langages d'ordres supérieurs. (Epsilon-safe languages and characterizations of higher order languages). - El Makki Voundy (2017)

Epsilon-reducible context-free languages and characterizations of indexed languages. - Séverine Fratani; El Makki Voundy (Inf. Comput., 2019)