1. Yu. I. Babenko, Common Topics in the Theory of Transient Combustion [in Russian], Nauka, Moscow (1972).
2. Yu. I. Babenko, Proceedings of the Fourth All-Union Conference on Heat and Mass Transfer [in Russian], Vol. 8, ITMO AN BSSR, Minsk (1972).
3. A. V. Letnikov, Mat. Sborn., Vol. 7, Moscow (1974).
4. E. Hille and R. Phillips, Functional Analysis and Semigroups [Russian translation], IL, Moscow (1962).
5. I. M. Gel'fand and G. E. Shilov, Generalized Functions and Operations on Them [in Russian], GIFML, Moscow (1959).