Mattson Company receives royalties on a patent it developed several years ago. Royalties are 4% of net sales, to be received on September 30 for sales from January through June and receivable on March 31 for sales from July through December. The patent rights were distributed on July 1, 2017, and Mattson accrued royalty revenue of $59,000 on December 31, 2017, as follows: General Journal Debit Credit Receivable - royalty revenue 59,000 Royalty revenue 59,000 Mattson received royalties of $63,900 on March 31, 2018, and $79,000 on September 30, 2018. In December, 2018, the patent user indicated to Mattson that sales subject to royalties for the second half of 2018 should be $790,000. Required: 1. Prepare any journal entries Mattson should record during 2018 related to the royalty revenue. (If no entry is required for a transaction/event, select "No journal entry required" in the first account field.)