It certainly looks similar though also different in some respects from what I have as
Campanula turczaninovii (
C. stevenii ssp. turczaninovii) from seeds collected by M. Pavelka at 3000m in the Sajan Mts., Russia.
On my plant, the buds are held upright (not reflexed as in your photos), the calyces are prominently white/furry (not obvious on your plant although the photos are too small to see all details), the flowers may be a darker blue-purple (though this may be a function of the photos themselves), and the leaves seem narrower.
In the Nicholls book,
Dwarf Campanulas, it's interesting that what he describes as
C. stevenii ("closely allied to C. patula") seems to be a much different plant from his description for
C. turczaninovii... a bit confusing!
Anyway, assuming my plant
is actually
C. turczaninovii (??), yours seems to have some differences. I wonder if your plant might be
C. collina? (If it eventually starts to run, as
C. collina does, that would be telling!)
