@article{TIMM_2016_22_1_a15,
     author = {E. A. Konovalchik and K. V. Kostousov},
     title = {Symmetrical $2$-extensions of a $2$-dimensional {grid.~I}},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {159--179},
     publisher = {mathdoc},
     volume = {22},
     number = {1},
     year = {2016},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2016_22_1_a15/}
}