Sarah, CPA, is engaged to audit the financial statements of Advanced Wholesaling for the year ended December 31, 2020. Sarah obtained and documented an understanding of the internal controls relating to the accounts receivable and assessed control risk at the minimum level. She requested and obtained from Advanced, an aged accounts receivable schedule listing the invoices by date and the total amount owed by each customer as of December 31, 2020 Sarah then sent positive confirmation requests to a sample of customers.

Required:

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