@article{ZNSL_2019_482_a3,
     author = {A. E. Guterman and E. M. Kreines and N. V. Ostroukhova},
     title = {2-words: their graphs and matrices},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {45--72},
     publisher = {mathdoc},
     volume = {482},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2019_482_a3/}
}