Seymour Ginsburg, Joseph S. Ullian. Ambiguity in context free languages. Journal of the ACM, 13(1):62-89, 1966. [doi]
@article{GinsburgU66,
title = {Ambiguity in context free languages},
author = {Seymour Ginsburg and Joseph S. Ullian},
year = {1966},
doi = {10.1145/321312.321318},
url = {http://doi.acm.org/10.1145/321312.321318},
tags = {context-aware},
researchr = {https://researchr.org/publication/GinsburgU66},
cites = {0},
citedby = {0},
journal = {Journal of the ACM},
volume = {13},
number = {1},
pages = {62-89},
}