1. A. A. Andreev, Proceedings of the 2nd International Seminar on Differential Equations and Applications (Samara, 1998), pp. 5–18.
2. M. Sh. Burlutskaya, V. P. Kurdyumov, A. S. Lukonina, and A. P. Khromov, Dokl. Math. 75, 399–402 (2007) [Dokl. Akad. Nauk 414, 443–446 (2007)].
3. V. A. Chernyatin, Substantiation of the Fourier Method in Mixed Problems for Partial Differential Equations (Mosk. Gos. Univ., Moscow, 1991) [in Russian].
4. A. N. Krylov, On Certain Partial Differential Equations with Engineering Applications (GITTL, Leningrad, 1950) [in Russian].
5. I. M. Rappoport, Asymptotic Methods in the Theory of Differential Equations (Akad. Nauk Ukr. SSR, Kiev, 1954) [in Russian].