1. Zhang Shisheng.Variational Inequalities and the Theory of Complementary Problems and Their Applications [M]. Shanghai: Shanghai Press of Science and Technology, 1991 (in Chinese)
2. Zhang Congjun, Zhang Shisheng. On recent developments and some open questions in the study of Browder-Hartman-Stampaccia variational inequality [J].J Math Res Exposition, 1995,15(2):313–317.
3. Panagiotopoulos P D. Inequality problems in mechanics and applications [A]. In:Convex and Nonconvex Energy Functions. Basel: Birkhauser, 1985, 10–25.
4. Hlavacek J, Haslinger J, Necas J, Lovisek J.Solution of Variational Inequalities in Mechanics [M]. New York: Springer, 1988.
5. Panagiotopoulos P D.Hemivariational Inequalities, Applications in Mechanics and Engineering [M]. Berlin: Springer-Verlag, 1993