@article{Harper:1993:FDL:138027.138060,
    Address = {New York, NY, USA},
    Author = {Harper, Robert and Honsell, Furio and Plotkin, Gordon},
    File = {A framework for defining logics (0) - a - a - r.pdf},
    ISSN = {0004-5411},
    Journal = {J. ACM},
    Keywords = {formal systems, interactive theorem proving, proof checking, typed lambda calculus},
    Month = {January},
    Number = {1},
    Pages = {143--184},
    Publisher = {ACM},
    Title = {A Framework for Defining Logics},
    URL = {http://doi.acm.org/10.1145/138027.138060},
    Volume = {40},
    Year = {1993},
    acmid = {138060},
    bdsk-url-1 = {http://doi.acm.org/10.1145/138027.138060},
    bdsk-url-2 = {https://doi.org/10.1145/138027.138060},
    date-added = {2019-08-10 15:41:15 +0200},
    date-modified = {2019-08-10 15:41:15 +0200},
    file-2 = {p143-harper (0) - a - a - r.pdf},
    issue_date = {Jan. 1993},
    numpages = {42},
    doi = {10.1145/138027.138060}
}

@article{Harper:1993:FDL:138027.138060, Address = {New York, NY, USA}, Author = {Harper, Robert and Honsell, Furio and Plotkin, Gordon}, File = {A framework for defining logics (0) - a - a - r.pdf}, ISSN = {0004-5411}, Journal = {J. ACM}, Keywords = {formal systems, interactive theorem proving, proof checking, typed lambda calculus}, Month = {January}, Number = {1}, Pages = {143--184}, Publisher = {ACM}, Title = {A Framework for Defining Logics}, URL = {http://doi.acm.org/10.1145/138027.138060}, Volume = {40}, Year = {1993}, acmid = {138060}, bdsk-url-1 = {http://doi.acm.org/10.1145/138027.138060}, bdsk-url-2 = {https://doi.org/10.1145/138027.138060}, date-added = {2019-08-10 15:41:15 +0200}, date-modified = {2019-08-10 15:41:15 +0200}, file-2 = {p143-harper (0) - a - a - r.pdf}, issue_date = {Jan. 1993}, numpages = {42}, doi = {10.1145/138027.138060} }