@misc{Heweliusz_Jan_(1611-1687)_Johannis,
 author={Heweliusz, Jan (1611-1687)},
 howpublished={online},
 publisher={[s.n.]},
 language={lat},
 title={Johannis Hevelii Epistola ad amicum de cometa anno MDCLXXVII Gedani observato [...]},
 type={starodruk},
}