how much gold is in the world

https://www.hardassetsalliance.com/blog/why-is-gold-valuable-the-5-reasons-most-investors-overlook#

https://en.wikipedia.org/wiki/Gold_reserve

http://www.sciencefocus.com/qa/how-much-gold-there-world

http://www.bbc.com/news/magazine-21969100

https://www.usmoneyreserve.com/blog/how-much-gold-is-in-the-world/

https://www.thebalance.com/which-countries-have-the-largest-gold-reserves-4151249

http://www.visualcapitalist.com/12-stunning-visualizations-of-gold-bars-show-its-rarity/

https://www.bullionstar.com/blogs/ronan-manly/worlds-central-banks-hold-gold-words/

https://io9.gizmodo.com/germany-s-post-world-war-i-scheme-to-extract-gold-from-499793752