1. 極東「ソ」領飛行場一覧圖 (黒河地方) | 五十万分一黒河地方素圖 -- Kyokutō "So" ryō hikōjō ichiran zu (Kokuga chihō) | 1:500,000 Kokuga chihō sozu, Maps Index Datasets Stanford University Public content 2023. Stanford Geospatial Center. This polygon shapefile is an index to the map series, '極東「ソ」領飛行場一覧圖 (黒河地方) | 五十万分一黒河地方素圖 -- Kyokutō "So" ryō hikōjō ichiran zu (Kokuga chihō) | 1:5... Stanford Digital Repository.