How to find Russian-language sites in other domain zones?

Question

Domain Name System

There is a task to find all Russian-language sites and go through them with a spider to collect certain statistical data.
For ru rf su domain zones, everything is simple, you can find domain name registries on the network, but for other domain zones this is already a problem, and we have quite a few Russian-language sites with the com domain zone in Runet.
How to be? How to find at least for the com zone Russian-language sites?
Are there registries or databases somewhere? Google didn't help

Answer 1

Empirical, I think. A domain is taken from the .ru zone and a check is run on other running TLDs. Or another way - just any Russian word is taken, transliterated and run through the running TLDs. This is of course a blind search, but in the general case, no one needs to make such lists ...

Answer 2

There are a huge number of sites in third level domains that are not in the available domain lists. And in general, not every site is even in search engines, not to mention that someone cataloged them. The problem is generally unsolvable.
But you can try to fight for the effectiveness of audience coverage with an incomplete set of sites. It is clear that most popular sites have a first-level domain in Russian zones, you can add popular sites from any ratings like alexa there. In general, there will already be a lot of information.