53In the third and last place, it should be recalled that, as is apparent from Article 76(4) of Regulation No 883/2004 and recitals 2 and 22 of Regulation No 987/2009, the proper functioning of the system established by Regulation No 883/2004 requires effective and close cooperation both between the competent institutions of the various Member States and between those institutions and persons falling within the scope of that regulation. Such cooperation is necessary for the purposes of determining the rights and obligations of the persons concerned and with a view to enabling them to access their rights as quickly as possible and under optimum conditions.