@article{Borowiecki:2018,
  author  = "M. Borowiecki and E. Drgas-Burchardt and E. Sidorowicz",
  title   = "P-apex graphs",
  journal = "Discussiones Mathematicae : Graph Theory",
  volume  = "Vol. 38",
  pages   = "323--349",
  year    = "2018",
}