@misc{Wiśnicki_Andrzej_An,
 author={Wiśnicki, Andrzej},
 howpublished={online},
 publisher={nakł. UMCS},
 language={eng},
 type={artykuł},
 title={An example of a nonexpansive mapping which is not 1-ball-contractive},
 keywords={matematyka},
}