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2. A. N. Kolmogorov, “On analytic methods in probability theory” [in Russian], Usp. Mat. Nauk 5, 5–41 (1938).
3. M.M. Lavrent’ev, K. G. Reznitskaya, and V. G. Yakhno, One-Dimensional Inverse Problems of Mathematical Physics [in Russian], Nauka, Novosibirsk, (1982).
4. V. S. Vladimirov, Equations of Mathematical Physics [in Russian], Nauka, Moscow (1981); English transl.: Marcel Dekker, New York (1971)..
5. G. I. Marchuk, “Mathematical modelling in a problem of environment” [in Russian], In: Mathematical Modelling. Modern Problems of Mathematical Physics and Numerical Mathematics, pp. 238–254, Nauka, Moscow (1989).