https://docs.google.com/document/d/1ChKe2XHsAmQ-HBK0xfbVZW0MDnU5Q6Lbl3huBIxPIXk/edit?usp=sharing
https://docs.google.com/document/d/1jc9cDm5vDYH2ICiNciYrslWG5-FSsyigRiGYyBJ17PM/edit?usp=sharing