An online spreadsheet for publisher HarperCollins viewed by The Associated Press on Thursday lists an "Untitled Bristol Palin Memoir" and shows that a planned release date of Aug. 16 has been moved up to June 21.
The book, included among "Adult S11 (Summer 2011) Changes," would be published by HarperCollins imprint William Morrow.
A similar listing was spotted earlier this week on Amazon.com but has since been pulled. Spokesman Seale Ballenger of Morrow has declined comment.
Palin's mother, former Alaska Gov. Sarah Palin, has published two best-sellers with HarperCollins.