@article{Grytczuk:2004,
  author  = "A. Grytczuk and B. Mędryk",
  title   = "Arithmetic functions and density of some classes of integer ideals",
  journal = "International Journal of Pure and Applied Mathematics",
  volume  = "Vol. 16",
  number  = "no 1",
  pages   = "93--100",
  year    = "2004",
}