author  = "A. Watras and A. Matraszek and P. Godlewska and I. Szczygieł and J. Wojtkiewicz and B. Brzostowski and G. Banach and J. Hanuza and J. Dereń",
  title   = "The role of the Ca vacancy in the determination of the europium position in the energy gap, its valence state and spectroscopic properties in KCa(PO3)3",
  journal = "Physical Chemistry Chemical Physics",
  volume  = "Vol. 16",
  number  = "no. 12",
  pages   = "5581--5588",
  year    = "2014",