各位仁兄：小弟写论文遇到两篇参考文献找不到，烦请各位仁兄伸出援助之手，在此先谢过。
第一篇：

Estimation of the shadow prices of pollutants with production/environment inefficiency taken into account: a nonparametric directional distance function approach Journal of Environmental Management, Volume 64, Issue 4, April 2002, Pages 365-375

Jeong-Dong Lee, Jong-Bok Park, Tai-Yoo Kim

第二篇：

Fare, R., Grosskopf, S., Lovell, C. A. K., & Yaisawarng, S. (1993). Derivation of shadow prices for undesirable outputs: A distance function approach. The Review of

Economics and Statistics, 75, 374–380.