[1] Clarke F H. Optimization and Nonsmooth Analysis. Philadelphia: SIAM, 1990

[2] Hasanov A, Liu Zhenhai. An inverse coefficient problem for a nonlinear parabolic variational inequality. Appl Math Lett, 2008 21(6): 563–570

[3] Kohn R, Vogelius M. Determining conductivity by boundary measurements. Commun Pure Appl Math, 1984, 37: 289–298

[4] Ladyzhenskaya O A. Boundary Value Problems in Mathematical Physics. New York: Springer, 1985

[5] Liu Zhenhai. On the identification of coefficients of semilinear parabolic equations. Acta Math Appl Sinica, 1994, 10: 356–367

[6] Liu Zhenhai. Identification of parameters in semilinear parabolic equations. Acta Mathematica Scientia, 1999, 19: 175–180

[7] Liu Zhenhai. A class of evolution hemivariational inequalities. Nonlinear Analysis, 1999, 36: 91–100

[8] Liu Zhenhai. Generalized quasi-variational hemivariational inequalities. Appl Math Lett, 2004, 17: 741–745

[9] Liu Zhenhai. Browder-Tikhonov regularization of non-coercive evolution hemivariational inequalities. In-verse Problems, 2005, 21: 13–20

[10] Liu Zhenhai. Existence results for quasilinear parabolic hemivariational inequalities. J Differ Equ, 2008, 244: 1395–1409

[11] Liu Zhenhai, Wang B Y. Coefficient identification in parabolic equations. Appl Math Compn, 2009, 209: 379–390

[12] Tikhonov A, Arsenin V. Solutions of Ill-Posed problems. New York: Wiley 1977

[13] Zeidler E. Nonlinear Functional Analysis and Its Applications II A/B. New York: Springer, 1990

[14] Chen H F. Recursive system identification. Acta Mathematica Scientia, 2009, 29B(3): 650–672

[15] Xu Y J, Liu Zhenhai. Controllability for a parabolic equation with a nonlinear term involving the state and the gradient. Acta Mathematica Scientia, 2010, 30B(5): 1593–1604