@misc{Vogel_Walther_(1880-1938)_Die,
 author={Vogel, Walther (1880-1938)},
 howpublished={online},
 publisher={Zentralverlag (Berlin)},
 language={niemiecki},
 title={Die Entstehung des modernen Weltstaatensystems},
 type={book},
 keywords={geopolitics, imperialism, political history, Germany},
}