@article{Martelli:1982:EUA:357162.357169,
    Address = {New York, NY, USA},
    Author = {Martelli, Alberto and Montanari, Ugo},
    File = {An Efficient Unification Algorithm - Martelli, Montanari (0) (0) - a - a - y.pdf},
    ISSN = {0164-0925},
    Journal = {ACM Trans. Program. Lang. Syst.},
    Keywords = {unification and classic},
    Month = {April},
    Number = {2},
    Pages = {258--282},
    Publisher = {ACM},
    Title = {An Efficient Unification Algorithm},
    URL = {http://doi.acm.org/10.1145/357162.357169},
    Volume = {4},
    Year = {1982},
    acmid = {357169},
    bdsk-url-1 = {http://doi.acm.org/10.1145/357162.357169},
    bdsk-url-2 = {http://dx.doi.org/10.1145/357162.357169},
    date-added = {2013-02-12 12:21:36 +0000},
    date-modified = {2013-02-12 12:21:56 +0000},
    issue_date = {April 1982},
    numpages = {25},
    doi = {10.1145/357162.357169}
}

@article{Martelli:1982:EUA:357162.357169, Address = {New York, NY, USA}, Author = {Martelli, Alberto and Montanari, Ugo}, File = {An Efficient Unification Algorithm - Martelli, Montanari (0) (0) - a - a - y.pdf}, ISSN = {0164-0925}, Journal = {ACM Trans. Program. Lang. Syst.}, Keywords = {unification and classic}, Month = {April}, Number = {2}, Pages = {258--282}, Publisher = {ACM}, Title = {An Efficient Unification Algorithm}, URL = {http://doi.acm.org/10.1145/357162.357169}, Volume = {4}, Year = {1982}, acmid = {357169}, bdsk-url-1 = {http://doi.acm.org/10.1145/357162.357169}, bdsk-url-2 = {http://dx.doi.org/10.1145/357162.357169}, date-added = {2013-02-12 12:21:36 +0000}, date-modified = {2013-02-12 12:21:56 +0000}, issue_date = {April 1982}, numpages = {25}, doi = {10.1145/357162.357169} }