@book{1930,
	author = {Conference on "Non-parametric and Semiparametric methods in Econometrics and Statistics", Duke Univ., May 18-20, 1988 and Barnett, William A.},
	title = {Nonparametric and semiparametric methods in econometrics and statistics},
	publisher = {Cambridge University Press,},
	year = {1991},
	address = {Cambridge:}
}