Hi KathyGibbons
The Referral Source is a column that can be added to reports such as the Sales [Customer Summary] report. This can be added by running the report, selecting Insert/Modify>>Show Hide before selecting that column from the list, and then Show.
Alternatively, you could look at filtering just by a particular or certain Referral Source. This is done by running the report such as the Sales [Customer Summary] report, selecting Filters>>Additional Filters>>Referral Source and selecting the appropriate source(s) before selecting Run Report.