1. Abgaryan, K.K., Reviznikov, D.L.: Numerical simulation of the distribution of charge carrier in nanosized semiconductor heterostructures with account for polarization effects. Comput. Math. Math. Phys. 56(1), 161–172 (2016)
2. Marchuk, G.I., Agoshkov, V.I.: Introduction to projection-grid methods. Nauka. The main editorial office of the physical and mathematical literature (1981)
3. Rectoris, K.: Variational methods in mathematical physics and engineering. Mir (1985)
4. Marchuk, G.I.: Methods of computational mathematics. Study guide. 3rd edn. Nauka. The main editorial office of the physical and mathematical literature (1989)
5. Mikhlin, S.G.: Variational methods in mathematical physics. Nauka. The main editorial office of the physical and mathematical literature (1970)