How I can learn xss bug?

Question

If you know which book or site is good please say?

Answer 1

https://excess-xss.com/
https://en.m.wikipedia.org/wiki/Cross-site_scripting
https://xss-game.appspot.com/
https://www.google.ru/about/appsecurity/learning/xss/
https://www.softwaretestinghelp.com/cross-site-scripting-xss-attack-test/
https://www.sololearn.com/discuss/1615440/?ref=app