por Spencer, Herbert, 1820-1903 [autor] | Varigny, Henry de, 1855- [traductor] | Mestral-Combremont, J [traductor] | Varigny, G. de [traductor] | Spencer, Herbert, 1820-1903. Autobiography.
por Langlois, Paul [autor] | Varigny, Henry de, 1855- [autor] | Richet, Charles, 1850-1935 [prologuista].