@article{Matkowski:1990,
  author  = "J. Matkowski",
  title   = "The converse of the Minkowski's inequality theorem and its generalization",
  journal = "Proceedings of the American Mathematical Society",
  volume  = "Vol. 109",
  number  = "no 3",
  pages   = "663--675",
  year    = "1990",
}