Judgment of the Court of 27 June 2000 in Joined Cases C-240/98 to C-244/98 (reference for a preliminary ruling from the Juzgado de Primera Instancia No 35 de Barcelona): Océano Grupo Editorial SA v Rocío Murciano Quintero (C240/98) and Salvat Editores SA v José M. Sánchez Alcón Prades (C-241/98), José Luis Copano Badillo (C-242/98), Mohammed Berroane (C-243/98) and Emilio Viñas Feliú (C-244/98) (Directive 93/13/EEC — Unfair terms in consumer contracts — Jurisdiction clause — Power of the national court to examine of its own motion whether that clause is unfair)