@article{ZNSL_2009_372_a7,
     author = {V. V. Makeev},
     title = {An extremal property of convex hexagons},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {93--96},
     publisher = {mathdoc},
     volume = {372},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2009_372_a7/}
}