@article{Drab:2007,
  author  = "M. Drab",
  title   = "An evaluation of the usability of sludge from the mechanical-biological sewage tratment plant of the town of Zielona Góra for sewage farming",
  journal = "Civil and Environmental Engineering Reports",
  volume  = "no 2",
  pages   = "9--17",
  year    = "2007",
  note    = "University of Zielona Góra Press, Zielona Góra",
}