#Proof-of-authentication:
   •   Bitcointalk username: hhttps://bitcointalk.org/index.php?action=profile;u=1972259
   •   Telegram username:@hongtan799
   •   Twitter username:@nguyenhongtan79
   •   Link to your tweet about Smart City Eco: https://twitter.com/nguyenhongtan79/status/1006072187457978368
   •   Facebook: https://www.facebook.com/tanttythdh
   •   Link to your Facebook post about Smart City Eco: https://www.facebook.com/tanttythdh/posts/261614927731534