Also, I hate to tell that, but the Crimean referendum was blatantly staged. Not that I'm saying that Russian would not have won it, but the ''YES'' were so high that it meant that over 80% of Ukrainian speakers and Tartars would have voted for it in addition of 100% of Russian speakers.
That the good old Tintin in the Land of Soviets style elections (those who vote for the communist list, raise one hand, those who are against, raise both...), where the good result might have been obtained, but the power that be decide that 60% is not enough and go for 99%.