You don't find them in the sense that you need to be looking for them. You just run as many calculators as you can that don't focus on just one ethnic group (ie: like the African test: puntDNAL K8 African only) and then look at your primary populations, mixed populations, 3-population, 4-population, etc, and keep a separate list of the averages of these. This is what I do to help balance and make patterns out of results. There is a K11 "turkic" calculator that you can look up here, but you need to run it yourself as it is not on GEDmatch. Check out my GEDmatch thread if you want to see the K11 and other calcs. I get a lot of Turkish matches in my secondary mixed populations as well as European matches:
https://www.theapricity.com/forum/sh...mp-DNA-Results
I would suggest that you keep running through calculators and keeping tabs on the results. FTDNA and 23 & me can also give slightly different percentages for the results, apparently. Some of the calculators on GEDmatch explicitly state if they are designed to be more optimizes for one company or the other. Hope this was helpful!