@misc{Johannes_de_Sacrobosco_(około_1195-1256)_Algorismus,
 author={Johannes de Sacrobosco (około 1195-1256)},
 address={Kraków},
 howpublished={online},
 publisher={Hochfeder, Kaspar ( -ca 1517). Druk.},
 language={lat},
 title={Algorismus},
 type={stary druk},
}