Feng, X. L., Zhang, H. J., & Wang, L. X. (1998). Quantitative evaluation of effects of water conservation forest on conserving soil and water in the upper stream of Miyun Reservoir. Journal of Beijing Forestry University, 20, 71-77.
 Hagemann, S. (2007). Applying ideal point estimation methods to the Council of Ministers. European Union Politics, 8, 279. http://dx.doi.org/10.1177/1465116507076433
 Hartanto, H., Prabhu, R., Widayat, A. S. E., & Asdak, C. (2003). Factors affecting runoff and soil erosion: Plot-level soil loss monitoring for assessing sustainability of forest management. Forest Ecology and Management, 180, 361-374. http://dx.doi.org/10.1016/S0378-1127(02)00656-4