User talk:Celso ad

Welcome!
Hello, Celso ad, and welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Here are some pages that you might find helpful: Please remember to sign your messages on talk pages by typing four tildes ( ~ ); this will automatically insert your username and the date. If you need help, check out Questions, ask me on my talk page, or ask your question on this page and then place  before the question. Again, welcome!
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Reliable sources
Hello, I'm DVdm. I noticed that you made a change to an article, Photon, 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 think I made a mistake, or if you have any questions, you can leave me a message on my talk page. See also wp:secondary sources. - DVdm (talk) 18:20, 25 May 2013 (UTC)