Columbia subject headings:
Bolzano, Bernard, 1781-1848.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.
Logic.
Harvard subject headings:
Bolzano, Bernard, 1781-1848--Logic.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716
Princeton subject headings:
Bolzano, Bernard, 1781-1848--Logic.
Leibniz, Gottfried Wilhelm, Freiherr von, 1646-1716.