Columbia subject headings:
Harvard subject headings:
Anarchism--History--19th century.
Anarchism--History--20th century.
Geography--Political aspects.
Kropotkin, Petr Alekseevich, kni︠a︡zʹ, 1842-1921
Metchnikoff, Léon, 1838-1888
Reclus, Elisée, 1830-1905.
Princeton subject headings:
Anarchism--History--19th century.
Anarchism--History--20th century.
Geography--Political aspects.