International organization and administration — European Economic Community — E.E.C. Treaty (Articles 30, 31 and 177) — Interpretation of — Measures having equivalent effect to quantitative restrictions on import of goods in free circulation — Whether including requirement of import licences issued automatically — Whether including imposition of penalties for failure to comply — Domestic courts of Member States from whose decisions there is no possibility of appeal under domestic law — Duty to refer matters concerning interpretation of E.E.C. Treaty to Court of Justice of European Communities for preliminary ruling — Whether required when meaning of Treaty clear — Whether required when Court of Justice has given interpretation in analogous case — The law of France