These include monographs (and their bibliographies), general reference materials, bibliographic databases and indexes, and images (slides, digital images, photographs, and photographic reproductions).

• 其中包括專著(和他們的書目)、一般參考資料、書目數據庫和指標和圖片(幻燈片、數字圖像、照片、和照片的複製品)。