How do I cite a biographical note?

To cite a biographical note, mention it in your prose and then include the work in your works-cited list:

According to a biographical note in Edith Wharton’s The Age of Innocence, the author “was born . . . into such wealth and privilege that her family inspired the phrase ‘keeping up with the Joneses.’”

Work Cited

Wharton, Edith. The Age of Innocence. Barnes and Noble Classics, 2004.