Multicenter study of creatinine- and/or cystatin C-based equations for estimation of glomerular filtration rates in Chinese patients with chronic kidney disease. oleh Jia-fu Feng, Ling Qiu, Lin Zhang, Xue-mei Li, Yu-wei Yang, Ping Zeng, Xiu-zhi Guo, Yan Qin, Hong-chun Liu, Xing-min Han, Yan-peng Li, Wei Xu, Shu-yan Sun, Li-qiang Wang, Hui Quan, Li-jun Xia, Hong-zhang Hu, Fang-cai Zhong, Rong Duan