Columbia subject headings:
Logic.
Lotze, Hermann, 1817-1881.
Mill, John Stuart, 1806-1873.
Sigwart, Christoph, 1830-1904.
Harvard subject headings:
Logic
Lotze, Hermann, 1817-1881.
Mill, John Stuart, 1806-1873
Sigwart, Christoph, 1830-1904.
Princeton subject headings: