@article{Warren_1977,
    doi = {10.1145/872736.806939},
    url = {https://doi.org/10.1145%2F872736.806939},
    year = {1977},
    month = {aug},
    publisher = {Association for Computing Machinery ({ACM})},
    number = {64},
    pages = {109--115},
    author = {David H D Warren and Luis M. Pereira and Fernando Pereira},
    title = {Prolog - the language and its implementation compared with Lisp},
    journal = {{ACM} {SIGART} Bulletin}
}

@article{Warren_1977, doi = {10.1145/872736.806939}, url = {https://doi.org/10.1145%2F872736.806939}, year = {1977}, month = {aug}, publisher = {Association for Computing Machinery ({ACM})}, number = {64}, pages = {109--115}, author = {David H D Warren and Luis M. Pereira and Fernando Pereira}, title = {Prolog - the language and its implementation compared with Lisp}, journal = {{ACM} {SIGART} Bulletin} }