I can put on some details.
1 At first about 6 months ago Putin conducted a census in all Russia including Chechnya where dear liberators counted about 1,100,000 people (really according to different sources there are hardly 400,000-500,000 population). So Putin called the number of people as big as the double real number. In other words now every voting would collect at least 50% of voices.
But as I see it wasn't necessary last time.
2 Another resource of getting right results is Federal soldiers in Chechnya - about 120,000 now. According to officials there were 400,000 participants of the referendum. So every soldier should have visited 3-4 polling places to make the necessary number of voters. If only Putin didn't have a simplier way to falsify the voting.
3 The results are 95-96% (why not 99.98% as during the Soviet era? - oh, I forgot Putin is a democrat
). It's interesting that the highest percentage of participation (about 90% of registered voters) has been achieved in the mountain Sharoy and Vedeno districts. Both districts are famous by the facts that local inhabitants almost totally left them due to brutal repressions from the Federals (now the most villages of the districts are waste) and there are the most active Resistance units (controlled by Doku Umarov and Shamil Basaev) dislocated (continuing regular attacks of course) - that's why reporters avoid visiting them. In the nothern Chechnya the percentage of voters is the smallest (about 50%) except some polling place in Ingushetia where the Federals have counted 190% (well done, comrades
).
4 According to witnesses the real number of voters among citizens is very small. For example in Achkhoy-Martan nobody (including local officials and militia) took part in the referendum, in Grozny one polling place was visited by seven people, in Ingushetia - by several dozens. All of them had been forced under threats of being left without product cards (a fresh joke: Why is Putin so brutal, leaving the refuges without bread? - At first he was going to be humanist - just to cut off electricity and water - but, after he discovered that the refuges had had already no water and electricity, he was to do nothing else but to deprive them of food).
5 The Kremlin has declared that the observers from the UN and OSCE have confirmed the legacy of the referendum. This is a BS - neither the UN nor OSCE sent their representatives. The only foreign organisation that took part in it was the Organisation of Islamic Conference - not a good example of democratic society IMHO.
Now some humor: one Russian TV reporter saw a big crowd of people waiting a bus at a bus-stop in Grozny, in the News program he called this crowd "a demonstration against the war in Iraq".