Both Lucy Riall's The Italian Risorgimento: State, Society, and National Unification and Derek Beales's The Risorgimento and the Unification of Italy. Both books are intended as introductory texts for unification. The latter also has a number of primary sources. Denis Mack Smith's biographies of Mazzini and Cavour are also accessible books. Risorgimento in Exile: Italian Émigrés and the Liberal International in the Post-Napoleonic Era by Maurizio Isabella is an attempt to examine unification from a transnational perspective.