 The research used documents of the Dutch East Indies Company in the archives of the Hague and Jakarta.Iwao's research and writing covered a broad range, including his early work on Japanese emigrant communities in South Asia and his later work on the Edo period of national seclusion ("sakoku").In a statistical overview derived from writings by and about Seiichi Iwao, OCLC/WorldCat encompasses roughly 100+ works in 200+ publications in 7 languages and 1,500+ library holdings.