Molecular characteristics of Brucella melitensis isolates from humans in Qinghai Province, China oleh Zhi-Jun Zhao, Ji-Quan Li, Li Ma, Hong-Mei Xue, Xu-Xin Yang, Yuan-Bo Zhao, Yu-Min Qin, Xiao-Wen Yang, Dong-Ri Piao, Hong-Yan Zhao, Guo-Zhong Tian, Qiang Li, Jian-Ling Wang, Guang Tian, Hai Jiang, Li-Qing Xu