"John Mahoney (visual voices guide)". Behind The Voice Actors. Retrieved November 15, 2023. A green check mark indicates that a role has been confirmed using a screenshot (or collage of screenshots) of a title's list of voice actors and their respective characters found in its credits or other reliable sources of information.
Levine, Ken (December 15, 2010). "How Frasier Came to Be". Kenlevine.blogspot.com. Archived from the original on September 11, 2012. Retrieved October 14, 2012.
Levine, Ken (December 15, 2010). "How Frasier Came to Be". Kenlevine.blogspot.com. Archived from the original on September 11, 2012. Retrieved October 14, 2012.