Who administers direct democracy mechanisms at the national level?

Article 132

The Constitutional Court exercises the attributionswhich are devolved on it by the Articles of the Constitution and the provisionsof the organic laws. It decides, moreover, on the regularity of the election ofthe members of Parliament and of the operations of referendum.                                                                                                                        

Nolegal documents were found that regulate the administration of a referendum.However, the Constitution provides that Constitutional Court decides on theoperations of referendum.