@article{TMF_1974_19_3_a12,
     author = {P. M. Slobodyan and I. V. Stasyuk},
     title = {Diagram technique for {Hubbard} operators},
     journal = {Teoreti\v{c}eska\^a i matemati\v{c}eska\^a fizika},
     pages = {423--429},
     publisher = {mathdoc},
     volume = {19},
     number = {3},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TMF_1974_19_3_a12/}
}