Columbia subject headings:
Darwin, Charles, 1809-1882.
Darwin, Emma Wedgwood, 1808-1896.
Livingstone, David, 1813-1873.
Livingstone, Mary, 1821-1862.
Marx, Jenny, 1814-1881.
Marx, Karl, 1818-1883.
Wives--Biography.
Harvard subject headings:
Darwin, Emma Wedgwood, 1808-1896.
Livingstone, Mary, 1821-1862.
Marx, Jenny, 1814-1881.
Wives--Great Britain--Biography.
Princeton subject headings:
Darwin, Charles, 1809-1882.
Darwin, Emma Wedgwood, 1808-1896.
Livingstone, David, 1813-1873.
Livingstone, Mary.
Marx, Jenny, 1814-1881.
Marx, Karl, 1818-1883.