@article{UZERU_2007_3_a2,
     author = {H. Ts. Hakopyan},
     title = {About convexity of polygons},
     journal = {Proceedings of the Yerevan State University. Physical and mathematical sciences},
     pages = {20--24},
     publisher = {mathdoc},
     number = {3},
     year = {2007},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/UZERU_2007_3_a2/}
}