http://www.smithsonianmag.com/smart-news/five-things-to-know-about-megacities-180958937/
http://webs.schule.at/website/Megacities/traffic_en.htm
http://www.telegraph.co.uk/finance/economics/11062542/The-rise-of-the-mega-city-will-change-the-global-economy-forever.html
https://en.wikipedia.org/wiki/Megacity
http://www.laweekly.com/news/los-angeles-roads-are-the-second-worst-in-america-5837280
https://en.wikipedia.org/wiki/Megacity#Slums