@article{Matkowski:1993,
  author  = "J. Matkowski and T. Świątkowski",
  title   = "Subadditive functions and partial converses of Minkowski's and Mulholland's inequalities",
  journal = "Fundamenta Mathematicae",
  volume  = "Vol. 143",
  number  = "no 1",
  pages   = "75--85",
  year    = "1993",
}