Columbia subject headings:
Harvard subject headings:
Eulenburg-Hertefeld, Philipp, Fürst zu, 1847-1921.
Lichnowsky, Karl Max, Fürst von, 1860-1928.
World War, 1914-1918--Causes
Princeton subject headings:
Eulenburg-Hertefeld, Philipp, Fürst zu, 1847-1921.
Lichnowsky, Karl Max, Fürst von, 1860-1928.
World War, 1914-1918--Causes.