User talk:2A02:1205:C6AD:C80:7470:FF21:22BA:1D94

Recent edit to Ulrich Sigwart
Hello, and welcome to Wikipedia. I noticed that you made a change to an article, Ulrich Sigwart, 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) 14:29, 29 February 2020 (UTC)