You can purchase XDCE-CROWD-SALE from these places
Go to Kucoin.com
The People's Exchange
Go to Bitfinex
The largest and most advanced cryptocurrencies exchange
Go to HitBTC
The most advanced cryptocurrency exchange to buy and sell Bitcoin, Ethereum, Litecoin, Monero, ZCash, DigitalNote, Ardor.
Go to Mercatox
