39. Li Lin^#, Jincan Zhang^#, Haisheng Su^#, Jiayu Li^#, Lunzhao Sun, Ruiwen Xue, Weihui Dang, Dingran Rui, Ai Leen Koh, Ning Kang, H. Q. Xu, Zhongqun Tian, Bin Ren, Hailin Peng*, and Zhongfan Liu*. Towards super-clean graphene. Nat. Commun. 2019, 10, 1912.