求助英文文献2篇！谢谢热心大侠！ 如题
作者：Becker, G.S.,
标题： Crime and punishment: an economic approach. Journal of Political Economy
期刊： Journal of Political Economy
卷： 76,169–217.
年：1968


作者：Harford, J.D.,
标题：Firm behavior under imperfectly enforceable pollution standards and taxes
期刊：Journal of Environmental Economics and Management
卷： 5: 26–43.
年：1978