@misc{Witzthum_de_Plan,
 author={Witzthum, de},
 address={[Petersburg]},
 howpublished={online},
 publisher={Dépôt topographique militaire},
 language={fre},
 language={rus},
 title={Plan de la ville de St. Petersbourg [...]},
 keywords={19 w., kartografia, plany miast, Petersburg (Rosja)},
}