You can purchase POA-NETWORK from these places
Go to Binance
To provide users with more secure and convenient block-chain asset exchange services, polymerization of global high-quality block chain assets, is committed to creating a world-class block chain asset trading platform.
Go to HitBTC
The most advanced cryptocurrency exchange to buy and sell Bitcoin, Ethereum, Litecoin, Monero, ZCash, DigitalNote, Ardor.