@article{Maciula:2016Rm,
  author = "Maciula, Rafal",
  title = "{Production of c bar c c bar c in single and double parton scattering in collinear and k_t-factorization approaches}",
  doi = "10.22323/1.234.0500",
  journal = "PoS",
  year = 2016,
  volume = "EPS-HEP2015",
  pages = "500"
}