Case F-63/08: Order of the Civil Service Tribunal (2nd Chamber) of 14 March 2013 — Christoph and Others v Commission (Civil Service — Non-permanent staff — Articles 2, 3a and 3b of the Conditions of employment of other servants (COS) — Temporary staff — Contractual staff — Auxiliary contractual staff — Duration of contract — Article 8 and 88 of the COS — Decision of the Commission of 28 April 2004 on the maximum duration for the recourse to non-permanent staff in the Commission services — Directive 1999/70/EC — Applicability to the institutions)