@conference {Nie92:owards,
	title = {owards a probabilistic modal logic for semantic-based information retrieval},
	booktitle = {Research and development on information retrieval - 15th ACM-SIGIR, Copenhagen},
	year = {1992},
	month = {jun},
	pages = {140-151},
	author = {Jian-Yun Nie}
}
