@article{Ajtai_1994,
    doi = {10.1016/s0022-0000(05)80071-6},
    url = {https://doi.org/10.1016%2Fs0022-0000%2805%2980071-6},
    year = {1994},
    month = {dec},
    publisher = {Elsevier {BV}},
    volume = {49},
    number = {3},
    pages = {562--588},
    author = {Miklos Ajtai and Yuri Gurevich},
    title = {Datalog vs first-order logic},
    journal = {Journal of Computer and System Sciences}
}

@article{Ajtai_1994, doi = {10.1016/s0022-0000(05)80071-6}, url = {https://doi.org/10.1016%2Fs0022-0000%2805%2980071-6}, year = {1994}, month = {dec}, publisher = {Elsevier {BV}}, volume = {49}, number = {3}, pages = {562--588}, author = {Miklos Ajtai and Yuri Gurevich}, title = {Datalog vs first-order logic}, journal = {Journal of Computer and System Sciences} }