Performance Enhancements and Parallel Algorithms for Two Multilevel Preconditioners. - Howard C. Elman; Xian-Zhong Guo (SIAM J. Sci. Comput., 1993)

Multi-p Preconditioners. - Ning Hu; Xian-Zhong Guo; I. Norman Katz (SIAM J. Sci. Comput., 1997)

Bounds for eigenvalues and condition numbers in the p-version of the finite element method. - Ning Hu; Xian-Zhong Guo; I. Norman Katz (Math. Comput., 1998)