1. https://www.coindesk.com/montana-passes-bill-to-exempt-utility-tokens-from-securities-laws2. https://bitcoinist.com/circle-cryptocurrency-laws-chilling-innovation/3. https://3dnews.ru/9861564. https://www.euronews.com/2019/05/23/hackers-hold-us-city-of-baltimore-to-ransom-demanding-13-bitcoins5. https://www.reddit.com/r/Elastos/comments/bt83x5/proposal_of_the_world_bank_group_poc_project/