User talk:86.15.234.67

This is your only warning; if you vandalize Wikipedia again, you may be blocked from editing without further notice. oknazevad (talk) 05:26, 22 November 2016 (UTC)

Please do not add or change content without citing a reliable source. Please review the guidelines at Citing sources and take this opportunity to add references to the article. Thank you. Materialscientist (talk) 05:23, 15 January 2017 (UTC)