@article{REAL228521,
          volume = {38},
          number = {3-4},
           title = {Arrow-t{\'i}pus{\'u} lehetetlens{\'e}gi t{\'e}telek},
          author = {J{\'o}zsef Mala},
            year = {2007},
           pages = {77--110},
         journal = {SZIGMA},
             url = {https://real.mtak.hu/228521/}
}