References
- Judge , G. G. , Griffiths , W. E. , Hill , R. C. , Lütkepohl , H. and Lee , T.-C. 1985 . The Theory and Practice of Econometrics , New York : John Wiley & Sons .
- Shepard , A. 1991 . Price discrimination and retail configuration . Journal of Political Economy , 99 : 30 – 53 .
- White , H. 1980 . A heteroskedasticity-consistent covariance matrix estimator and a direct test for heteroskedasticity . Econometrica , 48 : 817 – 838 .