- Data sources in Power BI Desktop: https://docs.microsoft.com/en-us/power-bi/desktop-data-sources
- Connecting to Excel in Power BI Desktop: https://docs.microsoft.com/en-us/power-bi/desktop-connect-excel
- Query overview in Power BI Desktop: https://docs.microsoft.com/en-us/power-bi/desktop-query-overview
- Common query tasks in Power BI Desktop: https://docs.microsoft.com/en-us/power-bi/desktop-common-query-tasks