#Proof-of-authentication:
   •   Bitcointalk username:Buihuyhoang
   •   Telegram username:@kendymen1
   •   Twitter username:@hoangbuihuy3
   •   Link to your tweet about Smart City Eco:https://twitter.com/SmartCityEco/status/1001103308675862528
   •   Facebook:https://www.facebook.com/hoang.h.hoang.58
   •   Link to your Facebook post about Smart City Eco:https://www.facebook.com/hoang.h.hoang.58/posts/1697681090348546