@article {MR2801384,
    AUTHOR = {Voisei, M. D. and Z{\u{a}}linescu, C.},
     TITLE = {A counter-example to `minimal distance between two non-convex
              surfaces'},
   JOURNAL = {Optimization},
  FJOURNAL = {Optimization. A Journal of Mathematical Programming and
              Operations Research},
    VOLUME = {60},
      YEAR = {2011},
    NUMBER = {5},
     PAGES = {593--602},
      ISSN = {0233-1934},
   MRCLASS = {90C30 (90C46)},
  MRNUMBER = {2801384},
       DOI = {10.1080/02331930903531535},
       URL = {http://dx.doi.org/10.1080/02331930903531535},
}