@article {Vok1997,
	title = {Collapsing multiway contingency tables: Simpson{\textquoteright}s paradox and homogenization},
	journal = {Behavior Research Methods, Instruments, \& Computers},
	volume = {29},
	number = {2},
	year = {1997},
	pages = {210{\textendash}215},
	publisher = {Springer-Verlag},
	author = {Vokey, John R}
}
