If you want more in-depth materials, then read through this copy of the great soviet encyclopedia in the section titled "Civil War and Military Intervention, 1918–20."

It also holds entire sections of additional names of sources and references of the encyclopedia. To reach it word search "October Revolution and Civil War, 1917-20"

You can compare it to what the great Russian encyclopedia says on the same period

Lenin on Peace Without Annexations and the Independence of Poland as Slogans of the Day in Russia. February 29, 1916

Lenin sending A Letter to the Polish Communists. October 19, 1921

An interview of Trotsky on the Polish Front. May 6 1920.

If you want an "unbiased" glimpse into the Civil War period, Kotkin's first book on Stalin covers the Civil war.