http://gordonua.com/day_question/kerry-i-putin-dogovorilis.html
http://www.zeit.de/politik/ausland/2015-05/boris-nemzow-russland-ukraine-wladimir-putin-krieg
http://www.bloombergview.com/articles/2015-05-12/gaming-the-ukraine-crisis
http://www.radiosvoboda.org/content/article/27012428.html
http://obozrevatel.com/blogs/45273-navischo-putinu-zustrich-z-kerri.htm