User talk:177.68.147.33

February 2019
Hello, I'm Doniago. I noticed that you added or changed content in an article, Air traffic control, 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. 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. In particular, please do not replace sourced material with unsourced material. DonIago (talk) 21:27, 12 February 2019 (UTC)
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