To find an item in the library, you will need the location, call number, and possibly a map. The call number provides information on the subject area and helps you locate the item on the shelf. It includes letters indicating the subject, numbers narrowing the subclass, a decimal and letters specifying the author. Items are arranged alphabetically and numerically by the different parts of the call number. Journals are alphabetical by title and shelved from oldest to newest, with the most recent in the current periodicals section. Assistance may be needed for certain materials like microfiche, government documents, or curriculum materials.