1. Lu Z, Chen Y, Huang Y: A priori error estimates for higher order variational discretization and mixed finite element methods of optimal control problems. J. Inequal. Appl. 2012., 2012: Article ID 95
2. Xu H: Efficient implementation of a modified and relaxed hybrid steepest-descent method for a type of variational inequality. J. Inequal. Appl. 2012., 2012: Article ID 93
3. Glowinski R: Numerical Methods for Nonlinear Variational Problems. Springer, Berlin; 2008.
4. Barrett JW, Prigozhin L: A quasi-variational inequality problem arising in the modeling of growing sandpiles. ESAIM, Math. Model. Numer. Anal. 2012. (accepted). doi:10.1051/m2an/2012062
5. Burke, S, Ortner, C, Suli, E: An adaptive finite element approximation of a generalised Ambrosio-Tortorelli functional. http://www2.maths.ox.ac.uk/oxmos/reports/pdfs/oxmos29.pdf