Can someone please explain this entry in detail.

Carnegie Corp. commissions, produces, and sells books through faith-based nonprofit organizations. The books are sold on the basis that a maximum of 50% of the quantity purchased can be returned within six months. The contract with the customer outlines the amount of consideration and the return policy and that payment is due within 30 days of the end of the return period. Carnegie has a good historical record of the proportion of books returned, on average. On 1 June, Carnegie sold $50,000 worth of books. On 15 August, $10,000 were returned, and on 3 October, an additional $10,000 were returned. The payment for the balance owing was received on 20 December. The cost of the books is 70% of the selling price. All of the returns are put back into inventory and can be resold. No Date General Journal Credit Debit 50,000 1 June Accounts receivable Revenue Refund Liability 25,000 25,000 1 June 17,500 Cost of goods sold Right to recovery asset recovery asset Inventory 17.500 35,000 15 August 10,000 Refund Liability Accounts receivable 10,000 15 August 7,000 Inventory Right to recovery asset 7,000 3 October 10,000 Refund Liability Accounts receivable 10,000 3 October 7,000 Inventory Right to recovery asset 7,000 December 01 5,000 Refund Liability Revenue 5,000 December 01 3,500 Cost of goods sold Right to recovery asset 3,500 December 20 30,000 Cash Accounts receivable 30,000