Sources: The ranges of data for a series or domain. Exactly one dimension must have a length of 1, and all sources in the list must have the same dimension with length 1. The domain (if it exists) & all series must have the same number of source ranges. If using more than one source range, then the source range at a given offset must be contiguous across the domain and series.
For example, these are valid configurations:
domain sources: A1:A5 series1 sources: B1:B5 series2 sources: D6:D10 domain sources: A1:A5, C10:C12 series1 sources: B1:B5, D10:D12 series2 sources: C1:C5, E10:E12