@article{IM2_1995_44_2_a3,
     author = {A. M. Gaisin},
     title = {On~a~conjecture of {Polya}},
     journal = {Izvestiya. Mathematics },
     pages = {281--299},
     publisher = {mathdoc},
     volume = {44},
     number = {2},
     year = {1995},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1995_44_2_a3/}
}