There is the gold standard by Robert Conquest and his book is “Harvest of Sorrow Soviet Collectivization and the Terror-Famine”
http://www.amazon.com/Harvest-Sorrow-Soviet-Collectivization-Terror-Famine/dp/0195051807
In November 2005, Conquest was awarded the Presidential Medal of Freedom.
Just ordered it.
I’ve heard of Conquest for years and have seen this work sited numerous times but have never been able to find a copy in any library or book store in this area. Since the Soviet Union fell apart before the age of the internet really took off, I guess I just never thought to check Amazon.