@article{TMF_1982_51_3_a13,
     author = {M. I. Auslender and M. I. Katsnel'son},
     title = {Effective spin {Hamiltonian} and phase separation in the almost half-filled {Hubbard} model and the narrow-band $s$-$f$ model},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {436--444},
     publisher = {mathdoc},
     volume = {51},
     number = {3},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1982_51_3_a13/}
}