From the Library of Congress: Here are some useful information on how to cite digitized sources in general, even if they are not primary sources.
Podcasting Websites
Podcasting is the creation of an audio show available in MP3 format via an RSS 2.0 feed. Podcasts can include talk shows, tutorials, essays, music, or other audio content. Users may select the podcast or audio feed that they wish to subscribe to.
"This I Believe, Inc., was founded in 2004 as a not-for-profit organization that engages youth and adults from all walks of life in writing, sharing, and discussing brief essays about the core values that guide their daily lives."
The mission of Storycorp is to provide Americans of all backgrounds and beliefs with the opportunity to record, share, and preserve the stories of our lives.