Anomalous Fluctuations and the period of Water Quantity Detuning, Their Significance in Groundwater Resources Developments, proceeding of the international symposium on Hydrogeology and Environment, Wuhan, China, 17-21 October 2000, China Environmental Science press 458-463 (ISTP)
Zhiha Chen, Hengli Xu, Scale Effect in soil Erosion Assessment, proceeding of the international symposium on Hydrogeology and Environment, Wuhan, China, 17-21 October 2000, China Environmental Science press 497-501 (ISTP)
Hengli Xu, Ziyong Sun and Rui Ma, Plant Underground Habit and Plant Species Stable Layer in Underground Habitat, proceeding of the international symposium on Water Resources and the Urban Environment, Wuhan, China, 9-10 November 2003,China Environmental Science press, 719-726
Ziyong Sun, Hengli Xu and Rui Ma, Eco-geological Mechanism of Patch Degradation in Ejina, The Lower Heihe River Basin, proceeding of the international symposium on Water Resources and the Urban Environment, Wuhan, China, 9-10 November 2003,China Environmental Science press, 713-718