What on earth has Kosovo got to do with this now then? Is it whataboutism? What is it?
There have not been any free/observed/internationally recognized referendums on Crimea. Most importantly, the referendum wasn't with blessing from Kyiv.
There was an annexaction which was partially done with military means and partially through a mock referendum. Both of those are blatant attacks on Ukrainian soverieignty.
Kosovo has 100% to do with this, friend. In case you are genuinely curious: The "West" has decided that Kosovo suddenly must be independent, and they bombed the shit out of Serbia (6mil pop, tiny) on a pretext that somehow this just HAS to be a separate entity. They didn't even bother with, as you say, a "mock referendum"!! Now the same people come lecturing about borders and sovereignty, and referendums, sounds cheap as shit.