@article{Alzer:2013,
  author  = "H. Alzer and J. Matkowski",
  title   = "A convexity property and a new characterization of Euler's gamma function",
  journal = "Archiv der Mathematik",
  volume  = "Vol. 100",
  number  = "no. 2",
  pages   = "131--137",
  year    = "2013",
}