Columbia subject headings:
Political geography.
Ratzel, Friedrich, 1844-1904.
Ratzel, Friedrich, 1844-1904. Politische geographie.
Harvard subject headings:
Political geography.
Ratzel, Friedrich, 1844-1904.
Ratzel, Friedrich, 1844-1904. Politische geographie.
Princeton subject headings:
Political geography.
Ratzel, Friedrich, 1844-1904.
Ratzel, Friedrich, 1844-1904. Politische geographie.