Xah Lee has written about it:
http://xahlee.info/comp/dvorak_keyboard_layout.html
http://xahlee.info/kbd/dvorak_and_all_keyboard_layouts.html
Tool to evaluate alternate layouts:
http://patorjk.com/keyboard-layout-analyzer/#/main
Other layouts:
https://normanlayout.info
https://viralintrospection.wordpress.com/2010/09/06/a-differ...
https://medium.com/@vojtajina/my-keyboard-layout-is-better-t...