Columbia subject headings:
Harvard subject headings:
Geometry--History--20th century.
Hilbert, David, 1862-1943.
Klein, Felix, 1849-1925.
Mathematicians--Germany--Biography
Pasch, Moritz, 1843-1930.
Princeton subject headings:
Geometry--History--20th century.
Hilbert, David, 1862-1943.
Klein, Felix, 1849-1925.
Mathematicians--Biography.
Pasch, Moritz, 1843-1930.