@article{IvaRud:69,
  journal = {Zastos. Mat.},
  volume = {10},
  title = {A pseudo-{B}oolean viewpoint on systems of representatives},
  author = {Iv{\u{a}}nescu, Petru and Rudeanu, Sergiu},
  year = {1969},
  fjournal = {Polska Akademia Nauk. Instytut Matematyczny. Zastosowania
              Matematyki},
  pages = {135--142},
}