@article{10_21136_CMJ_1965_100670,
     author = {Gruska, Jozef},
     title = {On structural unambiguity of formal languages},
     journal = {Czechoslovak Mathematical Journal},
     pages = {283--294},
     publisher = {mathdoc},
     volume = {15},
     number = {2},
     year = {1965},
     doi = {10.21136/CMJ.1965.100670},
     mrnumber = {0220549},
     zbl = {0133.25503},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.21136/CMJ.1965.100670/}
}