1. L. Bassotti, “Linear operators that are T -invariant with respect to a group of homeomorphisms,” Usp. Mat. Nauk,
43, No. 1, 57–85 (1988); English translation:
Russ. Math. Surv.,
43, No. 1, 67–101 (1988);
https://doi.org/10.1070/RM1988v043n01ABEH001538
.
2. I. C. Gohberg and M. G. Krein, Introduction to the Theory of Linear Nonself-Adjoint Operators in Hilbert Space [in Russian], Nauka, Moscow (1965); English translation:
3. American Mathematical Society, Providence, RI (1969).
4. N. Dunford and J. T. Schwartz, Linear Operators. Part III. Spectral Operators, Wiley Interscience, New York (1971).
5. A. A. Dezin, “Differential operator equations: A method of model operators in the theory of boundary value problems,” Tr. Mat. Inst. Steklova, Akad. Nauk SSSR,
229, 3–175 (2000);
http://mi.mathnet.ru/book242;
English translation:
Proc. Steklov Inst. Math.,
229, 1–161 (2000).