@article{Codd:CACM:1970,
    Address = {New York, NY, USA},
    Author = {Codd, E. F.},
    File = {codd\_unlocked (0) - a - a - q.pdf},
    ISSN = {0001-0782},
    Journal = {Commun. ACM},
    Keywords = {composition, consistency, data bank, data base, data integrity, data organization, data structure, derivability, hierarchies of data, join, networks of data, predicate calculus, redundancy, relations, retrieval language, security},
    Month = {June},
    Number = {6},
    Pages = {377--387},
    Publisher = {ACM},
    Title = {A Relational Model of Data for Large Shared Data Banks},
    URL = {http://doi.acm.org/10.1145/362384.362685},
    Volume = {13},
    Year = {1970},
    acmid = {362685},
    bdsk-url-1 = {http://doi.acm.org/10.1145/362384.362685},
    bdsk-url-2 = {https://doi.org/10.1145/362384.362685},
    date-added = {2018-11-23 19:46:48 +0100},
    date-modified = {2020-02-16 12:40:00 +0100},
    issue_date = {June 1970},
    numpages = {11},
    doi = {10.1145/362384.362685}
}

@article{Codd:CACM:1970, Address = {New York, NY, USA}, Author = {Codd, E. F.}, File = {codd_unlocked (0) - a - a - q.pdf}, ISSN = {0001-0782}, Journal = {Commun. ACM}, Keywords = {composition, consistency, data bank, data base, data integrity, data organization, data structure, derivability, hierarchies of data, join, networks of data, predicate calculus, redundancy, relations, retrieval language, security}, Month = {June}, Number = {6}, Pages = {377--387}, Publisher = {ACM}, Title = {A Relational Model of Data for Large Shared Data Banks}, URL = {http://doi.acm.org/10.1145/362384.362685}, Volume = {13}, Year = {1970}, acmid = {362685}, bdsk-url-1 = {http://doi.acm.org/10.1145/362384.362685}, bdsk-url-2 = {https://doi.org/10.1145/362384.362685}, date-added = {2018-11-23 19:46:48 +0100}, date-modified = {2020-02-16 12:40:00 +0100}, issue_date = {June 1970}, numpages = {11}, doi = {10.1145/362384.362685} }