Hello,

I need to find some details about advertising and marketing agencies
that work with the markets of central and eastern Europe (mainly in
Slovakia, Slovenia, Croatia, Ukraine, Serbia and Montenegro).

The answer should contain a decent number of agencies for each of the
above countries. In addition to the names of the agencies, some
contact information would be needed - a link to their website would be
best.
I need to know which media they use (billboards, transit, newspapers, TV, etc.)

I would rather get names of agencies who are in these countries but
agencies who are located in different countries and advertise in
central and eastern Europe are very welcome as well.

IMPORTANT NOTE: There are many fictitious companies and agencies in
central and eastern Europe. Make sure your sources are reliable.

Feel free to ask for clarifications.

Thanks.