Fraport Twin Star Management - Quality of services and customer satisfaction of passengers and airlines from the services provided by Civil airport for public use Burgas and Civil airport for public use Varna (annually conducted since 2011)
Steer Davis Gleave Limited Sucursal en Espana - Attitudes of actual and potential customers of public transport in the town of Bourgas
Port Varna - Levels of satisfaction of users from the services provided by Varna Port
Peer to Peer - Study among residents of Sofia - actual and potential customers of the services of "Sofia Public Transport Company - Sofia" Ltd.
Port Burgas - Specifics of the cruise sailing in the region of the Aegean, Marmara and Black Sea and coastal voyages in Bulgaria.