Open Procedure Aimed At Signing N. 4 Framework Agreements With A Single Economic Operator, With A Maximum Duration Of 48 Months For The Assignment Of Ordinary And Extraordinary Maintenance Works Of The Building Heritage Of Acer Campania In The Department Of Naples, In The Areas East 1 - Sub Zone E1, East 1 Sub Zone E2, West 1 Sub Zone W1 And West 1 Sub Zone W2