Cause Ana lysis of Groundwa ter Funnel in Langfang of Hebe i Prov ince
LIU Ba-Hua, CHEN Bao-Jiang, GONG Jin-Zhong, MA Xiu-Ling, BANG Jiu-Hui, ZHANG Xu-Dong
J4 . 2008, (2): 53 -56 .