Author
United States,
18
United States. Department of State
18
Italy
16
Italy,
16
United States. Department of State,
16
Australia,
1
Canada,
1
Canavari, Maurizio, 1964-
1
Denmark,
1
Finland,
1
France
1
France,
1
Germany
1
Great Britain
1
Great Britain,
1
Netherlands,
1
Norway,
1
Olson, Kent D.
1
Poland,
1
Spain,
1
SpringerLink (Online service)
1
Sweden,
1
Turkey,
1