@article{TIMM_2011_17_3_a23,
     author = {E. A. Neganova and V. I. Trofimov},
     title = {On symmetrical $4$-extensions of the grid $\Lambda^2$},
     journal = {Trudy Instituta matematiki i mehaniki},
     pages = {242--257},
     publisher = {mathdoc},
     volume = {17},
     number = {3},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/TIMM_2011_17_3_a23/}
}