@misc{Sperling_Johann_Tractatus,
 author={Sperling, Johann},
 howpublished={online},
 publisher={impensis haered. D. Tobiae Mevii},
 language={lat},
 title={Tractatus physicus de formatione horninis in utero},
 type={stary druk},
 keywords={Sperling, John (1603-1658), medycyna - historia, płód, rozprawa naukowa},
}