https://www.digital.archives.go.jp/item/en/2492470

[Items] "東宮御学問所幹事子爵小笠原長生外四名金杯下賜ノ件", 纂01564100-00700, National Archives of Japan Digital Archive, https://www.digital.archives.go.jp/item/en/2492470(accessed 2026-11-12)