Deustua, J. «SNELL, John L. Y Hans A. Schmitt: The Democratic Movement in Germany,1789-1914, The University of North Carolina Press, 197»6. Histórica, Vol. 1, n.º 2, Dec. 1977, pp. 295-9, http://revistas.pucp.edu.pe/index.php/historica/article/view/7809.