@article{Fabrika:2018Af,
  author = "Fabrika, Sergei N.",
  title = "{Ultraluminous X-ray sources. Optical data.}",
  doi = "10.22323/1.288.0046",
  journal = "PoS",
  year = 2018,
  volume = "APCS2016",
  pages = "046"
}