Have you entered the Russian keywords as tags in the Russian version of the KB article? Each language has its own tags (to find in search) or meta-words (to find in e.g. Google and other search engines).
7 months ago
@Kirill, The indexing of the articles generally takes sometime to reflect on the search autocomplete on the portal. And, as Mark mentioned, you can also use tags to boost the search relevance of the articles in search engines.