1. On measures of noncompactness and ideal variations in Banach spaces;Astala;Ann. Acad. Sci. Fenn. Ser. A I Math. Dissertationes,1980
2. The essential norm of an operator and its adjoint;Axler;Trans. Amer. Math. Soc.,1980
3. Measures of Noncompactness in Banach Spaces;Banaś,1981
4. Upper and lower Fredholm spectra;Buoni,1977
5. Calkin Algebras and Algebras of Operators on Banach Spaces;Caradus,1974