1. [1] P. Aiena, Fredholm and local spectral theory, with applications to multipliers, Kluwer, Dordrecht, 2004.
2. [2] P. Aiena and M. González, “Essentially incomparable Banach spaces and Fredholm theory”, Proc. Roy. Irish Acad. Sect. A 93:1 (1993), 49–59.
3. [3] P. Aiena and M. González, “On inessential and improjective operators”, Studia Math. 131:3 (1998), 271–287.
4. [4] P. Aiena and M. González, “Examples of improjective operators”, Math. Z. 233:3 (2000), 471–479.
5. [5] T. Álvarez, “Left-right Browder linear relations and Riesz perturbations”, Acta Math. Sci. Ser. B (Engl. Ed.) 37:5 (2017), 1437–1452.