1. Nakamoto, S., Bitcoin: A peer-to-peer electronic cash system, Bitcoin, 2009. https://bitcoin.org/bitcoin.pdf. Accessed December 1, 2019.
2. Amendment No. 4 to Form S-3 Registration Statement. Overstock.com, Inc., United States Security and Exchange Commission, 2015. https://www.sec.gov/Archives/edgar/data/1130713/000104746915008523/a2226515zs-3a.htm. Accessed December 1, 2019.
3. Notary, Bitcoin.com. https://notary.bitcoin.com. Accessed December 1, 2019.
4. Kempe, M., The land registry in the blockchain - testbed, ChromaWay, 2017. https://chromaway.com/papers/Blockchain_Landregistry_Report_2017.pdf. Accessed December 1, 2019.
5. Ali, M., et al., Blockstack: A global naming and storage system secured by blockchains, 2016 USENIX Annual Technical Conference, Denver, 2016, pp. 181–194.