Partial *-algebras of closed operators and their commutants. I. General structure J.-P. Antoine, F. Mathot (1987) Annales de l'I.H.P. Physique théorique
Partial *-algebras of closed operators and their commutants. II. Commutants and bicommutants J.-P. Antoine, F. Mathot, C. Trapani (1987) Annales de l'I.H.P. Physique théorique