@article{PDM_2011_13_a42,
     author = {M. B. Abrosimov and O. V. Modenova},
     title = {On properties of minimal extensions of orgraphs},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {84--85},
     publisher = {mathdoc},
     number = {13},
     year = {2011},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2011_13_a42/}
}