Thach Ngoc Nguyen Olga Kosheleva Vladik Kreinovich Hoang Phuong Nguyen Blockchains Beyond Bitcoin: Towards Optimal Level of Decentralization in Storing Financial Data. 163-167 2019 ECONVN https://doi.org/10.1007/978-3-030-04200-4_12 conf/econvn/2019 db/conf/econvn/econvn2019.html#NguyenKKN19