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[1] S. G. Mikhlin, Variatsionnye metody v matematicheskoi fizike, Gostekhizdat, Moskva–Leningrad, 1957
[2] N. I. Polskii, “O skhodimosti nekotorykh priblizhennykh metodov analiza”, Ukr. matem. zh., 7:1 (1956), 56–70 | MR
[3] M. I. Vishik, “Zadacha Koshi dlya uravnenii s operatornymi koeffitsientami, smeshannaya kraevaya zadacha dlya sistem differentsialnykh uravnenii i priblizhennyi metod ikh resheniya”, Matem. sb., 39(81) (1956), 51–148
[4] K. Moren, Metody gilbertova prostranstva, Mir, Moskva, 1965 | MR
[5] M. Sh. Birman, “Metody kvadratichnykh form v zadachakh o malom parametre pri starshikh proizvodnykh”, Vestnik LGU, 13:3 (1957), 9–12 | MR | Zbl
[6] L. A. Kalyakin, “Metod Rittsa dlya uravnenii s malym parametrom pri starshikh proizvodnykh”, Matem. zametki, 6:1 (1969), 91–96
[7] N. Danford, Dzh. T. Shvarts, Lineinye operatory. Obschaya teoriya, IL, Moskva, 1962