@article{Kozioł:2020,
  author  = "M. Kozioł and J. Kozioł",
  title   = "Circular Economy - Challenges for Mining and Power Generation as Exemplified by Poland",
  journal = "New Trends in Production Engineering",
  volume  = "Vol. 3",
  number  = "iss. 1",
  pages   = "56--68",
  year    = "2020",
}