Ferrara, City of the Renaissance, and its Po Delta _ Unesco.org:

http://whc.unesco.org/en/list/733/

Ferrara, City of the Renaissance, and its Po Delta _ Associazione Beni Italiani Patrimonio Mondiale Unesco: 

http://www.sitiunesco.it/?p=24%2F

Official Website for Ferrara and its Province:

http://www.ferraraterraeacqua.it/it/home-page

Municipality of Copparo _ Villa Mensa:

http://www.comune.copparo.fe.it/nqcontent.cfm?a_id=4886