Understanding the famine of the 1930s really has its roots in the economic debates in the early 20s.
https://www.amazon.com/Years-Hunger-Agriculture-1931-1933-Industrialisation/dp/0230238556
Lewins's Soviet Economic debate and stuff is a good background thing.
The years of hunger is a post soviet archive opening and basically opens saying it was not an intentional attempt to ethnically cleanse Ukrainians and there is nothing to suggest that it was.
The Years of Hunger is a pretty well researched external account of the famine by Davies and Wheatcroft. This is a quote from the book about its provisional conclusions:
"Although Stalin intentionally let starving people die, it is unlikely that he intentionally caused the famine to kill millions of people. It is also unlikely that Stalin used famine as a cheap alternative to deportation. True, the famine affected Ukraine severely; true, too, that Stalin distrusted the Ukrainian peasants and Ukrainian nationalists. Yet not enough evidence exists to show that Stalin engineered the famine to punish specifically the ethnic Ukrainians. The famine did not take place in an international political vacuum. The sharp rise in the foreign threat was likely to have been an important aggravating factor."