@misc{Orłowska_Ewa_Representation_1981,
 author={Orłowska, Ewa and Pawlak, Zdzisław},
 title={Representation of nondeterministic information},
 address={Warszawa},
 year={1981},
 type={raport},
 publisher={Instytut Podstaw Informatyki PAN},
}