@article{Valiant_1980,
    doi = {10.1016/0304-3975(80)90060-2},
    url = {https://doi.org/10.1016%2F0304-3975%2880%2990060-2},
    year = {1980},
    month = {nov},
    publisher = {Elsevier {BV}},
    volume = {12},
    number = {3},
    pages = {303--314},
    author = {L.G. Valiant},
    title = {Negation can be exponentially powerful},
    journal = {Theoretical Computer Science}
}

@article{Valiant_1980, doi = {10.1016/0304-3975(80)90060-2}, url = {https://doi.org/10.1016%2F0304-3975%2880%2990060-2}, year = {1980}, month = {nov}, publisher = {Elsevier {BV}}, volume = {12}, number = {3}, pages = {303--314}, author = {L.G. Valiant}, title = {Negation can be exponentially powerful}, journal = {Theoretical Computer Science} }