https://gigazine.net/news/20180412-looking-to-listen-google/

https://headlines.yahoo.co.jp/hl?a=20180412-00179922-nbnv-l23

https://this.kiji.is/356767216374563937

http://www.moj.go.jp/content/001254263.pdf http://www.moj.go.jp/content/001254262.pdf

https://www.j-cast.com/2018/04/12325976.html