Cassier Gilles: Mapping formula for functional calculus, Julia's lemma for operators and applications. In: Acta scientiarum mathematicarum, (74) 3-4. pp. 783-805. (2008)
Cassier Gilles; Chalendar Isabelle; Chevreau Bernard: New examples of contractions illustrating membership and non-membership in the classes Am,n. In: Acta scientiarum mathematicarum, (64) 3-4. pp. 707-731. (1998)