Hello Vlad Gurov, and welcome to Wikipedia. All or some of your addition(s) to Elliott Jaques have been removed, as they appear to have added copyrighted material without evidence of permission from the copyright holder. While we appreciate your contributions to Wikipedia, there are certain things you must keep in mind about using information from sources to avoid copyright and plagiarism issues here.

• You can only copy/translate a small amount of a source, and you must mark what you take as a direct quotation with double quotation marks (") and cite the source using an inline citation. You can read about this at Wikipedia:Non-free content in the sections on "text". See also Help:Referencing for beginners, for how to cite sources here.
• Aside from limited quotation, you must put all information in your own words and structure, in proper paraphrase. Following the source's words too closely can create copyright problems, so it is not permitted here; see Wikipedia:Close paraphrasing. (There is a college-level introduction to paraphrase, with examples, hosted by the Online Writing Lab of Purdue.) Even when using your own words, you are still, however, asked to cite your sources to verify the information and to demonstrate that the content is not original research.
• Our primary policy on using copyrighted content is Wikipedia:Copyrights. You may also want to review Wikipedia:Copy-paste.
• If you own the copyright to the source you want to copy or are a legally designated agent, you may be able to license that text so that we can publish it here. Understand, though, that unlike many other sites, where a person can license their content for use there and retain non-free ownership, that is not possible at Wikipedia. Rather, the release of content must be irrevocable, to the world, into the public domain (PD) or under a suitably-free and compatible copyright license. Such a release must be done in a verifiable manner, so that the authority of the person purporting to release the copyright is evidenced. See Wikipedia:Donating copyrighted materials.
• In very rare cases (that is, for sources that are PD or compatibly licensed) it may be possible to include greater portions of a source text. However, please seek help at Wikipedia:Media copyright questions, the help desk or the Teahouse before adding such content to the article. 99.9% of sources may not be added in this way, so it is necessary to seek confirmation first. If you do confirm that a source is public domain or compatibly licensed, you will still need to provide full attribution; see Wikipedia:Plagiarism for the steps you need to follow.
• Also note that Wikipedia articles may not be copied or translated without attribution. If you want to copy or translate from another Wikipedia project or article, you must follow the copyright attribution steps in Wikipedia:Translation#How to translate. See also Wikipedia:Copying within Wikipedia.

It's very important that contributors understand and follow these practices, as policy requires that people who persistently do not must be blocked from editing. If you have any questions about this, you are welcome to leave me a message on my talk page. Thank you. — Diannaa 🍁 (talk) 13:47, 24 January 2018 (UTC)[reply]

Hi, Vlad Gurov. Welcome to Wikipedia! Thank you for your contributions. I hope you like the place and decide to stay. Our intro page contains a lot of helpful material for new users—please check it out! If you need help, visit Wikipedia:Questions, ask me on my talk page, or ask a question on your talk page. The Mighty Glen (talk) 16:48, 28 February 2018 (UTC)[reply]

It's already been explained to you that copyrighted material can't be used in Wikipedia articles, but you've added more copyrighted text to Requisite organization from the book Survival to Growth. Please don't do this again. The Mighty Glen (talk) 16:49, 28 February 2018 (UTC)[reply]

@The Mighty Glen: It wasn't my edit. I haven't added that part of the text. Thank you Vlad Gurov (talk) 17:20, 28 February 2018 (UTC)[reply]

Argh. Sorry! You're absolutely right; please accept my apologies. The Mighty Glen (talk) 18:22, 28 February 2018 (UTC)[reply]

No worries. Vlad Gurov (talk) 18:27, 28 February 2018 (UTC)[reply]

Your addition to Project management has been removed, as it appears to have added copyrighted material to Wikipedia without evidence of permission from the copyright holder. If you are the copyright holder, please read Wikipedia:Donating copyrighted materials for more information on uploading your material to Wikipedia. For legal reasons, Wikipedia cannot accept copyrighted material, including text or images from print publications or from other websites, without an appropriate and verifiable license. All such contributions will be deleted. You may use external websites or publications as a source of information, but not as a source of content, such as sentences or images—you must write using your own words. Wikipedia takes copyright violations very seriously and persistent violators will be blocked from editing. — Diannaa 🍁 (talk) 14:23, 2 March 2018 (UTC)[reply]

@Diannaa: Sorry, done it by mistake. Forgot that I haven't paraphrased that part of the text before adding. Thank you.Vlad Gurov (talk) 15:23, 2 March 2018 (UTC)[reply]