[1] 録音録画再生機器のボタン - Wikipedia (2020-04-27 11:45:14 +09:00) https://ja.wikipedia.org/wiki/%E9%8C%B2%E9%9F%B3%E9%8C%B2%E7%94%BB%E5%86%8D%E7%94%9F%E6%A9%9F%E5%99%A8%E3%81%AE%E3%83%9C%E3%82%BF%E3%83%B3
[2] Media control symbols - Wikipedia (2020-05-07 23:23:30 +09:00) https://en.wikipedia.org/wiki/Media_control_symbols