Try all different Business Directories offered by Whitepages.it
Every Engine has different results,
Most companies are listed in serveral directories
but the results are not the same ...
Barilla by VB.com - other Brands by VB.com
Business to Consumers - Companies froviding Products or Sevices for End Users
B2C Directory Pagine Gialle
B2C Directory Yelp
Business to Business - Companies providing Products for Professionals
(example Manufacturer of Kitchens)
search in another country
Phone Book of the World.com
maybe the person you are looking for has moved
and can be cound through the directory of another country
search through the government
Italy Gov Search
this search engine goes through
all the Italian ministeries,
maybe the person you are looking for
has been mentioned at some point.
good luck ...