Sorry for bad English. I'm interested in how to translate only two words "Premium listings". Only they are in English, I need them to be in Russian. Never studied osclass. I work as a remote translator. And in which file it is located. All these words were left on the site only these two words. Thanks in advance.
http://s011.radikal.ru/i315/1703/ce/a4c1f1f5745d.png

@Michael
Take a look on our translation guide for osclass:
https://mb-themes.com/content/11-osclass-translations-themes-and-plugins

You need to translate all theme strings (+ plugins + core)