@article{PDM_2019_3_a10,
     author = {Yu. D. Ryazanov and S. V. Nazina},
     title = {Minimization of context-free grammars},
     journal = {Prikladna\^a diskretna\^a matematika},
     pages = {90--96},
     publisher = {mathdoc},
     number = {3},
     year = {2019},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/PDM_2019_3_a10/}
}