@article{Gottlob_2012,
    doi = {10.1145/2220357.2220363},
    url = {https://doi.org/10.1145%2F2220357.2220363},
    year = {2012},
    month = {jun},
    publisher = {Association for Computing Machinery ({ACM})},
    volume = {59},
    number = {3},
    pages = {1--35},
    author = {Georg Gottlob and Stephanie Tien Lee and Gregory Valiant and Paul Valiant},
    title = {Size and Treewidth Bounds for Conjunctive Queries},
    journal = {Journal of the {ACM}}
}

@article{Gottlob_2012, doi = {10.1145/2220357.2220363}, url = {https://doi.org/10.1145%2F2220357.2220363}, year = {2012}, month = {jun}, publisher = {Association for Computing Machinery ({ACM})}, volume = {59}, number = {3}, pages = {1--35}, author = {Georg Gottlob and Stephanie Tien Lee and Gregory Valiant and Paul Valiant}, title = {Size and Treewidth Bounds for Conjunctive Queries}, journal = {Journal of the {ACM}} }