@article{Romankiewicz:2018,
  author  = "R. Romankiewicz and F. Romankiewicz",
  title   = "Research on copper recovery from sledge from suspended copper concentrate reduction process",
  journal = "Metallurgy and Foundry Engineering",
  volume  = "Vol. 44",
  number  = "no. 3",
  pages   = "119--132",
  year    = "2018",
}