@article{AA_2021_33_4_a5,
     author = {I. G. Korepanov},
     title = {Heptagon relation in a direct sum},
     journal = {Algebra i analiz},
     pages = {125--140},
     publisher = {mathdoc},
     volume = {33},
     number = {4},
     year = {2021},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AA_2021_33_4_a5/}
}