\RBibitem{1}
\by Liu ZH, Papageorgiou N. S.,
\paper Double phase Dirichlet problems with unilateral constraints,
\jour Journal of Differential Equations
\yr 2022
\vol 316
\issue 15
\pages 249-269
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\by Liu ZH, Motreanu D., Zeng SD,
\paper Generalized penalty and regularization method for differential variational- hemivariational inequalities
\jour SIAM J. Optim.
\yr 2021
\vol 31
\issue 2
\pages 1158-1183
\RBibitem{3}
\by Liu ZH, Sofonea M.,Xiao Y.,
\paper Tykhonov well-posedness of a frictionless unilateral contact problem,
\jour Mathematics and Mechanics of Solids
\yr 2020
\vol 25
\issue 6
\pages 1294-1311
\RBibitem{4}
\by Liu ZH, Motreanu D., Zeng S.D.,
\paper Positive solutions for nonlinear singular elliptic equations of p-Laplacian type with dependence on the gradient,
\jour Calc. Var. PDE
\yr 2019
\vol 58
\issue 28
\pages 1-29
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\by Li XW, Liu ZH,
\paper Sensitivity analysis of optimal control problems described by differential hemivariational inequalities
\jour SIAM J. Comtrol Optim.
\yr 2018
\vol 56
\issue 5
\pages 3569-3597
