Sean Edwards, CPA, is engaged to audit the financial statements of Matthews Wholesaling for the year ended December 31, 2001. Edwards obtained and documented an understanding of the internal controls relating to the accounts receivable and assessed control risk relating to accounts receivable at the maximum level. Edwards requested and obtained from Matthews an aged accounts receivable schedule listing the total amount owed by each customer as of December 31, 2003, and sent positive confirmation requests to a sample of the customers.

Required:

What additional substantive audit procedures should Edwards consider applying in auditing the accounts receivable?