Embeddings of separable Banach star algebras into a Banach star algebra with one generator. Vladimir Müller (1988) Collectanea Mathematica
Exponentiating derivations of quasi * -algebras: possible approaches and applications. Bagarello, F., Inoue, A., Trapani, C. (2005) International Journal of Mathematics and Mathematical Sciences
Extension d'un théorème de von Neumann dans les a*-algèbres. Abdellah El Kinani (1998) Extracta Mathematicae
Extension of representations in quasi *-algebras J.-P. Antoine, F. Bagarello, C. Trapani (1998) Annales de l'I.H.P. Physique théorique