Some libraries also keep historical documents relevant to their particular town, and serve as a resource for historians in some instances. The Queens Public Library kept letters written by unrecognized Tiffany lamp designer Clara Driscoll, and the letters remained in the library until a curator discovered them. Some libraries may also serve as archives or government depositories, preserving historic newspapers, property records or government documents. Collections of unique or historical works are sometimes referred to as special collections; except in rare cases, these items are reference items, and patrons must use them inside the library under the supervision or guidance of a librarian. Local libraries' special collections may be of particular interest to people researching their family history. Libraries that are focused on collecting works related to particular families are genealogical libraries and may be housed in the same building as a public library.