@inbook {9960,
	title = {Endogenous Switching Regression Models for the Causes and Effects of Discrete Variables},
	booktitle = {Common Problems in Quantitative Social Research},
	year = {1988},
	publisher = {Sage Press},
	organization = {Sage Press},
	author = {Christopher Winship and Robert D. Mare},
	editor = {J. Scott Long}
}
