The Beijing angle closure progression study: design and methodology oleh Zhi-qiao Liang, Zhi-qiao Liang, Kang-yi Yang, Kang-yi Yang, Kun Lv, Kun Lv, Yao Ma, Yao Ma, Cun Sun, Ge Liang, Yan-kun Yue, Jia-yin Qin, Yao Zhao, Jia-nan Zhang, Qiong Yi, Xing-zhi Sun, Hui-juan Wu, Hui-juan Wu