@TechReport{economics.dp.2012-21,
 author = {Parroco, Anna Maria, Vaccina, Franco, De Cantis, Stefano, and Ferrante, Mauro},
 title = {Multi-destination Trips: A Survey on Incoming Tourism in Sicily},
 type = {Economics Discussion Paper},
 institution = {Kiel Institute for the World Economy},
 year = {2012},
 number = {2012-21},
 url = {http://www.economics-ejournal.org/economics/discussionpapers/2012-21}
}