User talk:193.138.115.229

Recent edit to Niels Dall
Hello, and welcome to Wikipedia. I noticed that you made a change to an article, Niels Dall, but you didn't provide a reliable source. It's been removed for now, but if you'd like to include a citation and re-add it, please do so! If you need guidance on referencing, please see the referencing for beginners tutorial, or if you think I made a mistake, you can leave me a message on my talk page. Thank you! Materialscientist (talk) 21:29, 22 February 2020 (UTC)