1. Bitcoin operating modes.
https://bitcoin.org/en/operating-modes-guide#introduction
. Accessed 12 May 2019
2. Coded Merkle tree library.
https://github.com/songzLi/coded_merkle_tree
3. Cryptonite.
http://cryptonite.info/
. Accessed 24 June 2019
4. Electrum bitcoin wallet.
https://electrum.org/#home
. Accessed 24 June 2019
5. Light ethereum subprotocol.
https://wiki.parity.io/Light-Ethereum-Subprotocol-(LES)
. Accessed 24 June 2019