@misc{Gemma_Frisius_De,
 author={Gemma, Frisius},
 howpublished={online},
 publisher={apud Greg. Bontium},
 publisher={apud Petrum Phalesium},
 language={lat},
 title={De radio astronomico et geometrico liber [...]},
 type={starodruk},
 keywords={astronomia, geometria, kąty, Mikołaj Kopernik},
}