@misc{Krug_Leopold_(1770-1843)_Die,
 author={Krug, Leopold (1770-1843)},
 address={Berlin},
 howpublished={online},
 publisher={Verlag von Duncker und Humblot},
 language={ger},
 type={książka},
 title={Die Provinz Ostpreussen. [Bd.] 1-3},
 keywords={Prusy Wschodnie, statsytyka},
}