@article{Aho_1971,
    doi = {10.1016/s0019-9958(71)90706-6},
    url = {https://doi.org/10.1016%2Fs0019-9958%2871%2990706-6},
    year = {1971},
    month = {dec},
    publisher = {Elsevier {BV}},
    volume = {19},
    number = {5},
    pages = {439--475},
    author = {A.V. Aho and J.D. Ullman},
    title = {Translations on a context free grammar},
    journal = {Information and Control}
}

@article{Aho_1971, doi = {10.1016/s0019-9958(71)90706-6}, url = {https://doi.org/10.1016%2Fs0019-9958%2871%2990706-6}, year = {1971}, month = {dec}, publisher = {Elsevier {BV}}, volume = {19}, number = {5}, pages = {439--475}, author = {A.V. Aho and J.D. Ullman}, title = {Translations on a context free grammar}, journal = {Information and Control} }