@article{VMUMM_1988_5_a14,
     author = {S. A. Zuev},
     title = {A lower bound for a percolation threshold for a square lattice},
     journal = {Vestnik Moskovskogo universiteta. Matematika, mehanika},
     pages = {59--61},
     year = {1988},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/VMUMM_1988_5_a14/}
}