1 . SOCIAL SECURITY FOR MIGRANT WORKERS - SOCIAL SECURITY BENEFITS - CALCULATION - APPORTIONMENT - CONDITION - AGGREGATION OF INSURANCE PERIODS ( EEC TREATY , ARTICLE 51 ; REGULATION NO 1408/71 OF THE COUNCIL , ARTICLE 46 ( 3 )) 2 . SOCIAL SECURITY FOR MIGRANT WORKERS - SOCIAL SECURITY BENEFITS - CALCULATION - RESIDENCE CLAUSE - WAIVER - CONSEQUENTIAL APPORTIONMENT - NOT PERMISSIBLE ( REGULATION NO 1408/71 OF THE COUNCIL , ARTICLES 10 AND 46 ( 3 ))