Geological characteristics and metallogenic age of Tengshan'ao Sn deposit in Dayishan of South Hunan and its prospecting significance oleh Zunzun Zhang, Yongyun Ning, Youyue Lu, Jingya Cao, Jianming Fu, Zhuang Zhao, Jian Guo, Liyan Ma, Zhengwei Qin, Jianfeng Li