@article {LucSetLie14,
    AUTHOR = {Luce, Robert and S{\`e}te, Olivier and Liesen, J{\"o}rg},
     TITLE = {Sharp parameter bounds for certain maximal point lenses},
   JOURNAL = {Gen. Relativity Gravitation},
  FJOURNAL = {General Relativity and Gravitation},
    VOLUME = {46},
      YEAR = {2014},
       EID = {1736},
}