The General Reading Room called "Atlantis" Unter den Linden represents the concept of the Historical Research Library with reference works and source materials related to the period before 1900 (subject history: until 1918).
Currently, there are around 140,000 items on the shelves, among them the current two years of ca. 650 history-related journals.

Classification scheme of the reference collections

• HA 1    Bibliographies, on shelves in the Information Centre (HA 1 A-G) and the Annex, 4th floor (HA 1 H-Z)
• HA 2    General Works, Encyclopedias, Library and Information Science, Media Studies, on shelves on the 2nd floor
• HA 3    Philosophy, Religion, Theology, on shelves on the 2nd floor
• HA 4    Psychology, Education, on shelves on the 2nd floor
• HA 5    Language and Literature, on shelves on the 2nd floor
• HA 6    Art, Prehistory, Archaeology, Music, on shelves on the 3rd floor
• HA 7    History, Ethnology, on shelves on the 2nd to 4th floor
• HA 8    Social Sciences, Public Administration and Political Science, Sports and Games, on shelves in the annex on the 3rd floor
• HA 9    Economy, on shelves in the annex on the 3rd floor
• HA 10  Law, on shelves in the annex on the 3rd floor
• HA 12  Mathematics, Natural Sciences (general), on shelves in the annex on the 3rd floor
• HA 13  Physics, Astronomy, Chemistry, on shelves in the annex on the 4th floor
• HA 14  Geosciences, on shelves in the annex on the 4th floor
• HA 15  Biology, Agriculture, on shelves in the annex on the 4th floor
• HA 16  Medicine, on shelves in the annex on the 4th floor
• HA 17  Technology, on shelves in the annex on the 4th floor