"No. 1939 内田家企画展 「四代佐七と内海焼」 開催中 | 教育長の窓" [No. 1939 Uchida family special exhibition “Fourth generation Sashichi and Utsumi ware” now being held | Superintendent’s window]. minamichita.ed.jp. Archived from the original on 27 October 2020.
"No. 1939 内田家企画展 「四代佐七と内海焼」 開催中 | 教育長の窓" [No. 1939 Uchida family special exhibition “Fourth generation Sashichi and Utsumi ware” now being held | Superintendent’s window]. minamichita.ed.jp. Archived from the original on 27 October 2020.