Petro Sapriianchuk

Welcome!

Hello, Petro Sapriianchuk! Welcome to Wikipedia! Thank you for your contributions. You may benefit from following some of the links below, which will help you get the most out of Wikipedia. If you have any questions you can ask me on my talk page, or place {{helpme}} on your talk page and ask your question there. Please remember to sign your name on talk pages by clicking or by typing four tildes "~~~~"; this will automatically produce your name and the date. If you are already excited about Wikipedia, you might want to consider being "adopted" by a more experienced editor or joining a WikiProject to collaborate with others in creating and improving articles of your interest. Click here for a directory of all the WikiProjects. Finally, please do your best to always fill in the edit summary field when making edits to pages. Happy editing! DVdm (talk) 20:49, 19 August 2019 (UTC) Getting Started Contributing to Wikipedia • Tutorial • Your first article The five pillars of Wikipedia • Simplified ruleset How to: edit a page • upload an image Getting Help Frequently Asked Questions Directories and indexes Where to: ask questions • make requests Tip of the day Request administrator attention Policies and Guidelines Neutral point of view • Reliable sources Verifiability • Citing sources • No original research What Wikipedia is not • Biographies of living persons Manual of Style (Simplified) • Three-revert rule Copyrights • Non-free content • Image use policy External links • Spam • Vandalism • Sock puppetry Deletion policy • Conflict of interest • Notability The Community Community Portal • Adopt-a-user program Assume good faith • Civility • Etiquette No personal attacks • Resolving disputes Build consensus • Village pump IRC channels • Mailing lists The Signpost (Wikipedia's newspaper) Things to do Be bold in editing • Help develop an article Maintenance • Peer review • Requested articles Join a WikiProject • Translating articles Cleaning up: General • Spam • Vandalism Miscellaneous Categories • Disambiguity • Stubs User pages • Talk pages Useful templates • Tools • User scripts

August 2019

Hello, I'm DVdm. I noticed that you made a change to an article, Electromagnetic radiation, but you didn't provide a source. I’ve removed it for now, but if you’d like to include a citation to a reliable source 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. Thanks. DVdm (talk) 19:34, 19 August 2019 (UTC)

Note: I have added some useful links at the top of your talk page. Regarding your request for help at Wikipedia:Help_desk#Editing_articles.: please have a careful look at one our key policies: wp:verifiability. Cheers. - DVdm (talk) 20:49, 19 August 2019 (UTC)