@misc{Büsching_Johann_Gustav_Von,
 author={Büsching, Johann Gustav},
 address={Breslau},
 howpublished={online},
 publisher={Kupfersche Druckerei},
 language={ger},
 title={Von Schlesischen Siegeln},
 keywords={Śląsk, historia, pieczęcie, sfragistyka},
}