@article{TMF_1989_80_3_a8,
     author = {A. F. Izmailov and A. R. Kessel},
     title = {Derivation of~the indirect interaction operator by~the path integral method. {Exact} results in~the $s-d$ exchange model},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {405--417},
     publisher = {mathdoc},
     volume = {80},
     number = {3},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1989_80_3_a8/}
}