See the Madison Wells, Audit Manager case to answer the question. Please give a detailed explanation for this question. Also, please identify the auditing standards for this question as well.

While reviewing the long-term debt workpapers, neither Madison nor Alanis discovered the critical error Blackwell had made when testing Le Prix's compliance with its debt covenants. What auditing standards, if any, dictate that audit workpapers be reviewed by senior members of an audit team? What is the overall nature and purpose of the audit workpaper review process and how thorough or detailed should workpapers be reviewed?