European Commission. (2001). Panorama of transport: Statistical overview of road, rail inland waterways and air transport in the European Union: data 1970-1999 (2001 edition.). Luxembourg: Office for Official Publications of the European Communities.
Παραπομπή Chicago StyleEuropean Commission. Panorama of Transport: Statistical Overview of Road, Rail Inland Waterways and Air Transport in the European Union: Data 1970-1999. 2001 edition. Luxembourg: Office for Official Publications of the European Communities, 2001.
Παραπομπή MLAEuropean Commission. Panorama of Transport: Statistical Overview of Road, Rail Inland Waterways and Air Transport in the European Union: Data 1970-1999. 2001 edition. Luxembourg: Office for Official Publications of the European Communities, 2001.