@article{Aho_1968,
    doi = {10.1016/s0019-9958(68)91087-5},
    url = {https://doi.org/10.1016%2Fs0019-9958%2868%2991087-5},
    year = {1968},
    month = {sep},
    publisher = {Elsevier {BV}},
    volume = {13},
    number = {3},
    pages = {186--206},
    author = {A.V. Aho and J.E. Hopcroft and J.D. Ullman},
    title = {Time and tape complexity of pushdown automaton languages},
    journal = {Information and Control}
}

@article{Aho_1968, doi = {10.1016/s0019-9958(68)91087-5}, url = {https://doi.org/10.1016%2Fs0019-9958%2868%2991087-5}, year = {1968}, month = {sep}, publisher = {Elsevier {BV}}, volume = {13}, number = {3}, pages = {186--206}, author = {A.V. Aho and J.E. Hopcroft and J.D. Ullman}, title = {Time and tape complexity of pushdown automaton languages}, journal = {Information and Control} }