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The Archives at Yale is for searching archival and manuscript collections held in Yale University. It provides information about “the creation, historical context, arrangement, and content of archival and manuscript collections as well as the information necessary for users to identify and request the portions relevant to their research.”
Orbis searches also reveal collections in Manuscripts and Archives. For example, searching "Japan" and "atomic bomb" as keywords in the advanced search box and specifying Manuscripts and Archives will bring up records of such collections as the Papers of George B. Darling, the executive director of the Atomic Bomb Casualty Commission in Hiroshima in 1957.