Syed S. Ali, Stuart C. Shapiro. Natural language processing using a propositional semantic network with structured variables. Minds and Machines, 3(4):421-451, 1993. [doi]
@article{AliS93,
title = {Natural language processing using a propositional semantic network with structured variables},
author = {Syed S. Ali and Stuart C. Shapiro},
year = {1993},
doi = {10.1007/BF00974105},
url = {http://dx.doi.org/10.1007/BF00974105},
researchr = {https://researchr.org/publication/AliS93},
cites = {0},
citedby = {0},
journal = {Minds and Machines},
volume = {3},
number = {4},
pages = {421-451},
}