@article{Synówka:2012,
  author  = "E. Synówka and S. Zontek",
  title   = "On optimality of the orthogonal block design",
  journal = "Discussiones Mathematicae : Probability and Statistics",
  volume  = "Vol. 32",
  number  = "no. 1-2",
  pages   = "59--68",
  year    = "2012",
}