@article{SM_1971_14_1_a2,
     author = {F. A. Berezin},
     title = {The number of closed nonselfintersecting contours on a~planar lattice},
     journal = {Sbornik. Mathematics},
     pages = {47--63},
     publisher = {mathdoc},
     volume = {14},
     number = {1},
     year = {1971},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1971_14_1_a2/}
}