You can run an Introduction Source patient report to get this information. Follow the steps below:
Click Reports > Patient.
Click New Report at the top-right of the page.
In the Report Type drop-down menu, select Introduction Source.
In the Created field, select a date range.
Set any other filters you desire.
RESULT: You will see a list of patients who were added to your Patient within the filters you set, as well as their introduction source.