Three letters of recommendation: A reference from an immediate supervisor An academic reference An academic or professional reference Letters of recommendation must be submitted electronically. When you register your reference writers through the application system, they will immediately receive an email with the link to the electronic reference form. For this reason, we suggest that you contact your references prior to registering them through the online application. References will have the option to upload a supporting letter in Word or PDF format. If you would like your references to receive the electronic form before you have completed the online application, you may go directly to the “Recommendations” link on the application and register your references before filling out the rest of the form. You can log back into your application to check which letters have been received, as well as to send reminder emails to your references.