++++ 1 . PROCEDURE - PRELIMINARY RULING - PARTIES TO THE MAIN ACTION - RIGHTS ( EEC TREATY, ARTICLE 177 ) 2 . FREE MOVEMENT OF PERSONS - WORKERS WITHIN THE MEANING OF REGULATION NO 3 OF THE COUNCIL OF THE EEC - CONCEPT 3 . FREE MOVEMENT OF PERSONS - WORKERS - ACCIDENT INSURANCE - BENEFITS GRANTED UNDER THE LEGISLATION OF A MEMBER STATE - INJURY SUSTAINED IN THE TERRITORY OF ANOTHER MEMBER STATE - INJURY SUSTAINED BEFORE THE ENTRY INTO FORCE OF REGULATION NO 3 OF THE COUNCIL OF THE EEC - INSTITUTIONS LIABLE FOR PAYMENT - RIGHTS WITH REGARD TO A THIRD PARTY LIABLE FOR COMPENSATION - ACTION FOR REIMBURSEMENT - ADMISSIBILITY ( REGULATION NO 3 OF THE COUNCIL OF THE EEC, ARTICLES 52 AND 53(3 ))