The development of the Library is based not only on the materials coming from the compulsory deposit of the printed materials, but also on some remarkable collections that especially characterise its shape and that are here briefly presented.
At the beginning the acquisitions were selected with the idea to enlarge ever more the competences of the Library, in accordance with the encyclopaedic ideal of that time.
From the 18th century to our days the Library has always continued to enrich its holdings with the purchase or the donation of new collections, with the aim to keep the existing assets and to specialise in some preferred topics.
The description of the collections of the Library is the easiest way to describe the characteristics of its holdings.
Nowadays just some collections have kept their topografical identity; on the other hand other collections were long ago dismantled in order to reshape their arrengement according to logical or functional criteria.
Deeper studies on the history of the Library may be found among its publications.
Among the existing collections we would like to point out (in Italian):
Since 2004 the Historical Archive Ricordi (Archivio Storico Ricordi) is hosted by the library.