@article{TRSPY_2011_275_a19,
     author = {A. Voynov},
     title = {A counterexample to {Valette's} conjecture},
     journal = {Informatics and Automation},
     pages = {301--303},
     publisher = {mathdoc},
     volume = {275},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/TRSPY_2011_275_a19/}
}