@article{Matkowski:1993,
  author  = "J. Matkowski",
  title   = "On a characterization of $L^p$-norm with the aid of the triangle inequality",
  journal = "Zeszyty Naukowe Politechniki £ódzkiej. Matematyka",
  volume  = "Nr 23",
  pages   = "77--91",
  year    = "1993",
  note    = "Politechnika £ódzka, £ód¼",
}