https://learn.microsoft.com/en-us/dax/
https://learn.microsoft.com/en-us/training/modules/dax-power-bi-write-formulas/2-formulas
https://learn.microsoft.com/en-us/dax/dax-syntax-reference
https://learn.microsoft.com/en-us/power-bi/transform-model/desktop-calculated-tables
https://learn.microsoft.com/en-us/power-bi/transform-model/desktop-calculated-columns