The second encirclement campaign against the Eyuwan Soviet was an encirclement campaign launched by the Chinese Nationalist Government against the Eyuwan Soviet, a Communist base located in the border region between Hubei, Henan, and Anhui provinces. The Fourth Red Army responded with its second counter-encirclement campaign and successfully defended the soviet. It lasted from April 1931 to July 1931.
Military History Research Department, Complete History of the People's Liberation Army, Military Science Publishing House in Beijing, 2000,