1. Nihyakumanbunnoichi Daitōa Kōkūzu, Maps Index Datasets Stanford University Public content 1943. Stanford Geospatial Center. This polygon shapefile is an index to 1:2,000,000 scale maps of East Asia, Southeast Asia, Alaska, titled '二百万分一大東亜航空圖 - Nihyakumanbunnoichi Daitōa... Stanford Digital Repository.