^Osipkov, I.; Vasserman, E. Y.; Hopper, N.; Kim, Y. Combating Double-Spending Using Cooperative P2P Systems: 41. 2007. doi:10.1109/ICDCS.2007.91.
^Joshua Kopstein. The Mission to Decentralize the Internet. The New Yorker. 12 December 2013 [30 December 2014]. The network’s "nodes"—users running the bitcoin software on their computers—collectively check the integrity of other nodes to ensure that no one spends the same coins twice. All transactions are published on a shared public ledger, called the "block chain"