@article{SM_1969_9_4_a1,
     author = {L. A. Skornyakov},
     title = {Characterization of the category of polygons},
     journal = {Sbornik. Mathematics},
     pages = {455--465},
     publisher = {mathdoc},
     volume = {9},
     number = {4},
     year = {1969},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1969_9_4_a1/}
}