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School quality and black-white relative earnings : a direct assessment
Card, David E., (1991)
Card, David E., (1992)
School Quality and Black-White Relative Earnings : A Direct Assessment
Card, David E., (2021)
An introduction to classical econometric theory
Ruud, Paul Arthur, (2000)
Restricted least squares subject to monotonicity and concavity constraints
Ruud, Paul Arthur, (1997)
Nonparametric multivariate regression subject to constraint
Goldman, Steven M., (1993)