Qi Shi* , Chen Gao* , Wei Zhou , Bao-Yun Zhang , Jian-Ming Chen , Chan Tian , Hui-Ying Jiang , Jun Han , Ni-Juan Xiang , Xiao-Fang Wang , Yong-Jun Gao and Xiao-Ping Dong
BMC Public Health 2008, 8:360doi:10.1186/1471-2458-8-360