Case C-338/09: Judgment of the Court (Third Chamber) of 22 December 2010 (reference for a preliminary ruling from the Unabhängiger Verwaltungssenat Wien — Austria) — Yellow Cab Verkehrsbetriebs GmbH v Landeshauptmann von Wien (Freedom to provide services — Freedom of establishment — Competition rules — Cabotage transport operations — National transportation of persons by bus service — Application to operate a service — Licence — Authorisation — Conditions — Requirement of a seat or permanent establishment in the national territory — Reduction of income compromising the profitability of a service already licensed)