The handbook contains papers of constitutional lawyers and political scientists presented at an international conference held at the Centre for Studies on Federalism in ApriI 2005. The papers reflect the academic customs and style of the different authors and countries. The reports have been inspired by the following "Working Model", but not adapted to Italian writing or editing rules. The research was occasioned by the project of an Italian "Federal Senate" adopted by the government majority under the last legislature but rejected by referendum in 2006. Massimo Carli offered a special contribution on the institutional representation of local bodies at the regionallevel in Italy, available at the Centre address (in Italian language). Most national reporters have also managed the translations. Others have been realised by Mariangela Ronzitti and Monica Ricco. The users of the handbook can obtain the original versions at the Centre address. Anna Mastromarino, Demis Bessi, Pamela Martino and Pier Luigi Petrillo prepared the Italian version of a specific database on various second chambers not represented by the national reports. The database is available on the Centre website (www.csfederalismo.it).