https://gigazine.net/news/20180720-legally-download-3d-printed-gun/

http://www.nikkei-science.com/201809_078.html

https://books.rakuten.co.jp/rk/fdda9b83549c30c183a1b017ff3b540a/ https://www.amazon.co.jp/gp/customer-reviews/R3NUJS2PI6U2K3/ref=cm_cr_arp_d_rvw_ttl?ie=UTF8&ASIN=4313511652

https://www.nikkei.com/article/DGXMZO33220940Q8A720C1CC1000/

http://blog.livedoor.jp/schulze/archives/52217887.html