@misc{Popa_Valeriu_A,
 author={Popa, Valeriu},
 howpublished={online},
 publisher={Wydawnictwo Uniwersytetu Śląskiego},
 publisher={De Gruyter Open},
 language={eng},
 type={artykuł},
 title={A general fixed point theorem for implicit cyclic multi-valued contraction mappings},
 keywords={matematyka},
}