@article{PDMA_2020_13_a30,
     author = {O. I. Egorushkin and I. V. Kolbasina and K. V. Safonov},
     title = {Geometric condition of formal grammars solvability},
     journal = {Prikladnaya Diskretnaya Matematika. Supplement},
     pages = {106--108},
     publisher = {mathdoc},
     number = {13},
     year = {2020},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDMA_2020_13_a30/}
}