You're not going to find many books to the effect of, "see how hegemonic we aren't", so you mainly need to look at how the ussr treated republics within it, and especially preserved national minorities.
The USSR academy of sciences published works in many languages, same for the state publishing houses.
There are also some longer works on the languages of the USSR, because there was such a diversity of them and the constitution mandated their protection, but I haven't read them.
Compare with the US (wiped out every indigenous language), or the UK (tried to do the same for Irish and Welsh). It's always projection with these anticommunist westerner historians.
You can see the diversity here https://en.m.wikipedia.org/wiki/Languages_of_the_Soviet_Union