Columbia subject headings:
Harvard subject headings:
Hegel, Georg Wilhelm Friedrich, 1770-1831--Contributions in philosophy of nature--Congresses.
Philosophy of nature--History--19th century--Congresses.
Science--History--19th century--Congresses.
Princeton subject headings:
Hegel, Georg Wilhelm Friedrich, 1770-1831--Congresses.
Science--Philosophy--Congresses.