1. Helemskiĭ A. Ya., Banach and Normed Algebras: General Theory, Representations, Homology [Russian], Nauka, Moscow (1989).
2. Murphy G., C* -Algebras and Operator Theory, Academic Press, Boston (1990).
3. Coburn L. A., “The C* -algebra generated by an isometry,” Bull. Amer. Math. Soc., vol. 73, no. 5, 722–726 (1967).
4. Coburn L. A., “The C* -algebra generated by an isometry. II,” Trans. Amer. Math. Soc., vol. 137, 211–217 (1969).
5. Douglas R. G., “On the C* -algebra of a one-parameter semigroup of isometries,” Acta Math., vol. 128, 143–152 (1972).