How many people were affected during the famine? Are there any sources for Soviet records on the Golodomor?
According to the official internal Soviet statistics, the number of excessive mortality in Ukraine in 1932-1933 was 1,532,700 people, of which 1 million 385 thousand in 1933.
A paradoxical fact of this is that in 1933 the total harvest for the USSR was 69 million tonnes (some think this number is overestimation due to the counting method used in the USSR and the actual harvest was about 50 million tonnes), compared to average 35 million tonnes during the war, which did not cause a hunger. The shipment of grain abroad was also drastically cut in 1933. The harvest of fish in 1933 was also very good.
From 19 March 1932 to 4 July 1933 the government shipped additional 1 million tonnes of food to Ukraine at expense of other regions.
It should be noted also that the most of deaths happened in June and July of 1933, during the summer, an non-typical time for hunger.
Another peculiarity of the deaths was that there were no reports of dystrophy which is typical for any historical hunger, including that of 1920s in Volga region, of 1947 and of the siege of Leningrad, as well as hungers in India. Instead, there were numerous reports of widespread tumescence.
It was conjectured by some historians that the actual reason for the excess deaths was a liver disease due to consumption of defective grain.
This could happen because a serious portion of grain was hidden from the state agents or stolen from the kolkhoz fields. The farmers could not purify and winnower their grain themselves because the necessary equipment was transferred to the kolkhozes in the course of collectivization.
It is known that consumption of such grain leads to exactly the same symptoms as those reported for the victims.
Also there were no reported cases of mortality in cities, which always consumed properly processed grain.
Kosior in his report to Stalin wrote:
Overall the picture was the same: where the less were procurements, the higher was mortality.
It should be noted also that there were reported numerous cases where grain storages were found in households where all the family members were found dead.
Kosior wrote to Stalin:
According to one GPU repot,
Given these reports and the harvest statistics (which was known to Stalin) it is possible to suggest that Stalin possibly thought that there was enough food available and the farmers intentionally had hidden it and starved due to their own greed.
From Wikipedia: http://en.wikipedia.org/wiki/Holodomor#Death_toll
The Western authorities on this are Robert Conquest (Harvest of Sorrow) and Timothy Snyder, already mentioned. Robert Conquest gives an estimate of 4 millions. Snyder is somewhat more conservative.
But we will never know the exact number: the earliest census after this was forged, and those who did it exterminated.
EDIT. In one comment a method of "asking random Ukrainians" is proposed. I am a Ukrainian, and my grandparents survived it, by escaping from a village to a large city (Kharkiv) shortly before it began. I lived in Ukraine for 36 years, and have heard plenty of eyewitness accounts.