User talk:185.220.12.74

October 2022
Hello, I'm ToastGuard. I noticed that you added or changed content in an article, Nonlinear acoustics, but you didn't provide a reliable source. It's been removed and archived in the page history for now, but if you'd like to include a citation and re-add it, please do so. You can have a look at referencing for beginners. If you think I made a mistake, you can leave me a message on my talk page. Thank you. Toast  (talk)  15:05, 19 October 2022 (UTC)

April 2023
Hello, I'm TLJ7863. I wanted to let you know that one or more of your recent contributions have been undone because they did not appear constructive. If you would like to experiment, please use the sandbox. If you have any questions, you can ask for assistance at the Teahouse or the Help desk. Thanks. TLJ7863 (talk) 16:53, 14 April 2023 (UTC)