Priblizhennye metody resheni︠i︡a operatornykh uravneniĭ i ikh prilozheni︠i︡a - Apar︠t︡sin, A. S.; Belʹt︠i︡ukov, Boris Alʹbertovich, 1926- (Akademi︠i︡a nauk SSSR, Sibirskoe otd-nie, Sibirskiĭ ėnerg. in-t, 1982)