https://www.businessinsider.com/royal-family-net-worth-worlds-richest-billionaires-ranked-2018-5
Europe royalty: https://www.businessinsider.com/royal-family-net-worth-europe-ranked-2018-5#1-prince-hans-adam-ii-liechtenstein-10
Prince Albert:
http://www.palais.mc/en/princely-family/h-s-h-prince-albert-ii/biography-1-5.html
https://www.hellomagazine.com/royalty/2014031417515/prince-albert-monaco-birthday-facts/
https://www.telegraph.co.uk/news/worldnews/europe/monaco/6894991/Monaco-to-build-into-the-sea-to-create-more-space.html
https://www.rt.com/business/410925-monaco-expand-mediterranean-dwell-wealthy/
https://philly.curbed.com/2017/2/1/14468882/grace-kelly-philadelphia-home-opening-date-museum
https://www.visitmonaco.com/us/blog/22686/the-astounding-private-collection-of-the-princes-of-monaco
Emir Qatar
https://www.thebalance.com/sovereign-wealth-funds-3305969
https://www.businessinsider.in/ranked-the-17-biggest-private-luxury-yachts-in-the-world/16-katara-124-metres-/-408-feet-a-superyacht-with-a-mysterious-origin-the-katara-apparently-has-a-qatari-flag-when-it-docks-boat-international-thinks-it-belongs-to-the-new-young-emir-sheikh-tamim-bin-hamad-al-thani-/slideshow/52433180.cms
https://www.nytimes.com/2018/01/22/world/middleeast/qatar-saudi-emir-boycott.html
https://www.marketwatch.com/story/qatar-boycott-has-dragged-on-too-long-pompeo-says-2019-01-13
https://www.bloomberg.com/news/articles/2018-09-18/qatar-s-qia-chief-is-said-to-leave-320-billion-sovereign-fund
https://www.therichest.com/rich-list/rich-countries/the-reasons-behind-how-dubai-became-so-rich/
https://www.khaleejtimes.com/business/corporate/dubai-holding-appoints-amit-kaushal-as-ceo
https://www.bloomberg.com/news/articles/2019-01-31/dubai-holding-to-develop-mega-project-near-burj-al-arab
https://www.investopedia.com/terms/a/abu-dhabi-investment-authority-adia.asp
https://www.onlinevolunteering.org/en/node/388486
Liechtenstein
https://www.forbes.com/2004/06/02/cx_0602hot.html#7227f97a74d9
https://www.wien.info/en/sightseeing/museums-exhibitions/top/liechtenstein-city-palace
https://www.bloomberg.com/news/articles/2017-10-26/europe-s-richest-royal-gets-richer-as-family-bank-lures-wealthy
https://www.cheatsheet.com/money-career/the-richest-royal-in-the-world-may-surprise-you-hint-its-not-queen-elizabeth-ii.html/?a=viewall
Mohamed VI morocco
https://awsa.org.au/new-book-exposes-the-absurd-spending-of-king-mohamed-vi-of-morocco/
https://www.nytimes.com/2015/09/02/world/europe/french-publisher-wont-print-book-on-moroccan-king-after-authors-arrest.html
https://www.forbes.com/2009/06/17/king-morocco-phosphate-business-billionaires-royal-conflict.html#f86ef5941f6c
king salman
http://time.com/4972313/king-salman-escalator/
https://www.worldatlas.com/articles/which-is-the-largest-residential-palace-in-the-world.html
https://www.cbsnews.com/pictures/10-luxurious-perks-of-being-the-new-saudi-king/9/
sultan brunei
https://www.worldatlas.com/articles/which-is-the-largest-residential-palace-in-the-world.html