Peter Van Roy. A useful extension to Prolog s definite clause grammar notation. SIGPLAN Notices, 24(11):132-134, 1989. [doi]
@article{Roy89:0,
title = {A useful extension to Prolog s definite clause grammar notation},
author = {Peter Van Roy},
year = {1989},
doi = {http://doi.acm.org/10.1145/71605.71617},
tags = {Prolog, grammar},
researchr = {http://researchr.org/publication/Roy89%3A0},
cites = {0},
citedby = {0},
journal = {SIGPLAN Notices},
volume = {24},
number = {11},
pages = {132-134},
}