@misc{Alphonsus_de_Spina_Fortalitium,
 author={Alphonsus de Spina},
 address={Norimbergae},
 howpublished={online},
 publisher={Koberger Anton},
 language={lat},
 type={inkunabuł},
 title={Fortalitium fidei},
 keywords={Incunabula -- Poland -- Bydgoszcz -- Catalogs, Early printed books -- 15th century},
}