Commission Regulation (EU) No 1372/2013 of 19 December 2013 amending Regulation (EC) No 883/2004 of the European Parliament and of the Council on the coordination of social security systems and Regulation (EC) No 987/2009 of the European Parliament and of the Council laying down the procedure for implementing Regulation (EC) No 883/2004 Text with relevance for the EEA and for Switzerland