@article {MR1773178,
    AUTHOR = {Penot, Jean-Paul and Z{\u{a}}linescu, Constantin},
     TITLE = {Harmonic sum and duality},
   JOURNAL = {J. Convex Anal.},
  FJOURNAL = {Journal of Convex Analysis},
    VOLUME = {7},
      YEAR = {2000},
    NUMBER = {1},
     PAGES = {95--113},
      ISSN = {0944-6532},
   MRCLASS = {49N15 (52A05 52A30 90C25 90C46)},
  MRNUMBER = {MR1773178 (2001i:49061)},
MRREVIEWER = {Alberto Seeger},
}