@article{Perlman1999,
	title = {Lattice conditional independence models for contingency tables with
	non-monotone missing data patterns},
	author = {Michael D. Perlman and Lang Wu},
	day = {01},
	journal = {Journal of Statistical Planning and Inference},
	month = {Jul},
	number = {2},
	pages = {259--287},
	url = {http://www.sciencedirect.com/science/article/B6V0M-3WWT9FF-7/1/8b3ad7b508457bece7ea0c222996eda5},
	volume = {79},
	year = {1999},
	biburl = {http://www.bibsonomy.org/bibtex/2430db4541b3c8a04aa29c7a9b43d9012/smicha},
	keywords = {imported }
}