Ding, Shoujun, Zhang, Qingli, Dou, Renqin, Liu, Wenpeng, Ma, Yufei, Wang, Xiaofei, Sun, Guihua, Gu, Changjiang, Luo, Jianqiao, Yan, Renpeng, AND Sun, Dunlu. " Progress of niobate laser materials" Quarterly Physics Review [Online], Volume 4 Number 3 (1 July 2018)