@inproceedings{Rounds:1970:TPT:800161.805156,
    Address = {New York, NY, USA},
    Author = {Rounds, William C.},
    BookTitle = {Proceedings of the Second Annual ACM Symposium on Theory of Computing},
    Keywords = {no pdf},
    Location = {Northampton, Massachusetts, USA},
    Pages = {109--116},
    Publisher = {ACM},
    Series = {STOC '70},
    Title = {Tree-oriented Proofs of Some Theorems on Context-free and Indexed Languages},
    URL = {http://doi.acm.org/10.1145/800161.805156},
    Year = {1970},
    acmid = {805156},
    bdsk-url-1 = {http://doi.acm.org/10.1145/800161.805156},
    bdsk-url-2 = {http://dx.doi.org/10.1145/800161.805156},
    date-added = {2014-05-06 15:22:02 +0000},
    date-modified = {2014-05-06 15:22:08 +0000},
    numpages = {8},
    doi = {10.1145/800161.805156}
}

@inproceedings{Rounds:1970:TPT:800161.805156, Address = {New York, NY, USA}, Author = {Rounds, William C.}, BookTitle = {Proceedings of the Second Annual ACM Symposium on Theory of Computing}, Keywords = {no pdf}, Location = {Northampton, Massachusetts, USA}, Pages = {109--116}, Publisher = {ACM}, Series = {STOC '70}, Title = {Tree-oriented Proofs of Some Theorems on Context-free and Indexed Languages}, URL = {http://doi.acm.org/10.1145/800161.805156}, Year = {1970}, acmid = {805156}, bdsk-url-1 = {http://doi.acm.org/10.1145/800161.805156}, bdsk-url-2 = {http://dx.doi.org/10.1145/800161.805156}, date-added = {2014-05-06 15:22:02 +0000}, date-modified = {2014-05-06 15:22:08 +0000}, numpages = {8}, doi = {10.1145/800161.805156} }