Columbia subject headings:
Harvard subject headings:
Goethe, Johann Wolfgang von, 1749-1832
Humboldt, Alexander von, 1769-1859.
Kant, Immanuel, 1724-1804
Natural history
Natural history--Germany--History.
Natural history--Philosophy
Princeton subject headings:
Goethe, Johann Wolfgang von, 1749-1832.
Humboldt, Alexander von, 1769-1859.
Kant, Immanuel, 1724-1804.
Natural history--Germany--History.
Natural history--Philosophy.