– REGULATION (EC) No 883/2004 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 29 April 2004 on the coordination of social security systems. https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32004R0883&from=EN   – REGULATION (EC) No 987/2009 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 16 September 2009 laying down the procedure for implementing Regulation (EC) No 883/2004 on the…