1) DeutschAkademie online German course is the most comprehensive and easy to understand German grammar course.
Learn more: https://www.deutschakademie.de/online-deutschkurs/russisch
2) Deutsche Welle’s free German language courses give you the opportunity to learn the language the way you like.
Learn more: http://startdeutsch.ru/
3) Learn German for free and in groups: search for learning materials for different levels and on different topics, and add them to your learning lists.
Learn more: https://www.goethe.de/prj/dfd/de/home.cfm
4) The multilingual resource Deutsch.info offers educational content and practical advice for people travelling to or living in Germany and Austria. There is also a Russian language version.
Learn more: https://deutsch.info/courses
5) Studygerman.ru is aimed at a diverse audience, from inexperienced pupils to teachers. There are 10 lessons online dedicated to learn German basics, articles, nouns, adjectives, pronouns and verbs.
Learn more: https://www.studygerman.ru/