@article{Głazowska:2007,
  author  = "D. Głazowska and J. Matkowski",
  title   = "An invariance of geometric mean with respect to Lagrangian means",
  journal = "Journal of Mathematical Analysis and Applications",
  volume  = "Vol. 331",
  number  = "no 2",
  pages   = "1187--1199",
  year    = "2007",
}