@article{DM_2009_21_3_a3,
     author = {V. S. Krotkin and O. V. Kuzmin},
     title = {On a~constructive approach to the calculation of cardinality of the {Ryser} classes},
     journal = {Diskretnaya Matematika},
     pages = {33--36},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2009_21_3_a3/}
}