Related Questions:
Update Referral Field
Edit Referral source choices
How do I add another referral source?
How do I add a referral source category?
Procedure:
Please note, that only admin users have access to perform this action. If you are part of a chain, you will be able to choose which Organization/s the new Referral Source can be used in.
Select Settings
Select Fields -> Setup Values
Click Edit next to Referral Source
Click +New Referral Source
Enter the new Referral Source under Value Name
Select All Organizations or which specific Organization/s should have access to this option
Click Create