@article {MR3817765,
    AUTHOR = {Brenner, Susanne C. and Gedicke, Joscha and Sung, Li-yeng},
     TITLE = {{$C^0$} interior penalty methods for an elliptic distributed
              optimal control problem on nonconvex polygonal domains with
              pointwise state constraints},
   JOURNAL = {SIAM J. Numer. Anal.},
  FJOURNAL = {SIAM Journal on Numerical Analysis},
    VOLUME = {56},
      YEAR = {2018},
    NUMBER = {3},
     PAGES = {1758--1785},
      ISSN = {0036-1429},
   MRCLASS = {49J20 (65K15 65N30)},
  MRNUMBER = {3817765},
MRREVIEWER = {Michael Hinterm\"{u}ller},
       DOI = {10.1137/17M1140649},
       URL = {https://doi.org/10.1137/17M1140649},
}