Cases C-482/00, C-497/00, C-498/00 and C-499/00: Reference for a preliminary ruling by the Tribunale Amministrativo Regionale per il Lazio by judgments of that court of 6 July 2000 in the cases of Aziende Agricole Ettore Raffa and Others v Azienda di Stato per gli Interventi nel Mercato Agricolo (AIMA) and the Ministry of the Treasury, the Budget and Planning (Case C-482/00); Azienda Agricola Gonal di Gonzato Simone e Stefano (C-497/00), Azienda Agricola Gianluigi Cerati and Maria Ceriali s.s. v AIMA and the Ministry of the Treasury, the Budget and Planning (Case C-498/00), and Musini Nicolò Giovanni Maria v AIMA and the Ministry of the Treasury, the Budget and Planning (Case C-499/00)