https://docs.google.com/document/d/1yeGv8jkY0DLGWSpAubBP_K87ZpQGcP6Lf4LITtXKoSw/edit?usp=sharing
https://docs.google.com/document/d/1xirqbTuyaiQ1f4Rethga_vmQeFCZO0TKH3RI9p5OWv0/edit?usp=sharing