[1] Chen XX. Obstruction to the existence of metric whose curvature has umbilical hessian in a K-surface. Communication in Analysis and Geometry, 2000, 8(2): 267~299

[2] Lin CS, Zhu XH. Explicit construction of extremal Hermitian metric with finite conical singularities on S². Communications in Analysis and Geometry, 2002, 10(1): 177~216

[3] Chen Q, Wu YY. Existences and explicit constructions of HCMU metrics on S² and T². Accepted by Pacific Journal of Mathematics

[4] Forster O. Lectures on riemann surfaces, GTM 81. Springer-Verlag, 2001

[5] Chen Q, Chen XX, Wu YY. The structure of HCMU metric in a K-surface. International Mathematics Research Notices, 2005(16): 941~958

[6] Wu YY. Some problems about HCMU metrics: . Hefei: University of Science and Technology of China, 2005(in Chinese) 吴英毅. 关于HCMU度量的几个问题: .合肥:中国科学技术大学,2005

[7] Gilbarg D, Trudinger NS. Elliptic partial differential equations of second order. Reprint of the 1998 edition. Springer, 2001