Columbia subject headings:
Harvard subject headings:
Astronomy--History
Humboldt, Alexander von, 1769-1859.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Mathematics--History.
Princeton subject headings:
Astronomy--History.
Humboldt, Alexander von, 1769-1859.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Mathematics--History.