Columbia subject headings:
Harvard subject headings:
Africa, Southern--Discovery and exploration, Portuguese.
Explorers--Africa, Southern--Biography
Explorers--Portugal--Biography
Ivens, Roberto, 1850-1898
Princeton subject headings:
Africa, Southern--Discovery and exploration, Portuguese.
Explorers--Africa, Southern--Biography.
Explorers--Portugal--Biography.
Ivens, Roberto, 1850-1898.