Columbia subject headings:
Friedrich, Caspar David, 1774-1840--Notebooks, sketchbooks, etc.
Friedrich, Caspar David, 1774-1840--Travel--Germany--Harz Mountains.
Harvard subject headings:
Friedrich, Caspar David, 1774-1840--Journeys--Germany--Harz Mountains.
Friedrich, Caspar David, 1774-1840--Notebooks, sketchbooks, etc.
Harz Mountains (Germany)--In art
Princeton subject headings:
Friedrich, Caspar David, 1774-1840.
Landscape painting.
Romanticism in art.