http://www.toptenz.net/top-10-famous-deadly-swords.php
http://www.storypick.com/sword-history/
https://en.wikipedia.org/wiki/Curtana
https://en.wikipedia.org/wiki/Joyeuse
https://en.wikipedia.org/wiki/Wallace_Sword
https://en.wikipedia.org/wiki/Tizona
https://en.wikipedia.org/wiki/El_Cid
http://www.ancient-origins.net/artifacts-other-artifacts/goujian-ancient-chinese-sword-defied-time-003279
https://en.wikipedia.org/wiki/Sword_of_Goujian
https://en.wikipedia.org/wiki/Seven-Branched_Sword
https://en.wikipedia.org/wiki/Zulfiqar
https://www.thevintagenews.com/2016/07/13/top-10-famous-deadly-swords-history/
http://www.ancient-origins.net/artifacts-other-artifacts/searching-honjo-masamune-lost-samurai-sword-power-005807