@article{ZNSL_1990_183_a2,
     author = {E. P. Golubeva},
     title = {On distribution of the integral $2\times2$ matrices},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {49--55},
     year = {1990},
     volume = {183},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1990_183_a2/}
}