Columbia subject headings:
Harvard subject headings:
Humboldt, Alexander von, 1769-1859--Notebooks, sketchbooks, etc.
Humboldt, Alexander von, 1769-1859--Travel--Italy.
Scientific expeditions--Italy--History--19th century.
Princeton subject headings:
Humboldt, Alexander von, 1769-1859--Notebooks, sketchbooks, etc.
Humboldt, Alexander von, 1769-1859--Travel--Italy.
Scientific expeditions--Italy--History--19th century.