http://r6.ca/blog/20180225T160548Z.html
origin - https://www.pipiscrew.com/2018/02/why-is-it-taking-20-minutes-to-mine-this-bitcoin-block/ why-is-it-taking-20-minutes-to-mine-this-bitcoin-block
http://r6.ca/blog/20180225T160548Z.html
origin - https://www.pipiscrew.com/2018/02/why-is-it-taking-20-minutes-to-mine-this-bitcoin-block/ why-is-it-taking-20-minutes-to-mine-this-bitcoin-block