You're welcome. I'm glad that this topic interests not only me. In general, quite a lot was written in the second half of the 19th century about the differences between the Russian and Siberian ethnic groups. These were: Slovtsov, Shchapov, Potanin, Yadrintsev, and others, the so-called regionalists. However, almost all of them ended up in a bad way. There were also the so-called Eurasianists, who simply stated that Russia is not only made up of Russians. Russia is Eurasia, populated by Eurasian peoples who are close in spirit.