Robin Bush, Nahdlatul Ulama and the Struggle for Power Within Islam and Politics in Indonesia, Institute of Southeast Asian Studies, 2009, ISBN9812308768, page 111
Robert Cribb (2002). "Unresolved Problems in the Indonesian Killings of 1965-1966". Asian Survey. 42 (4): 550–563. doi:10.1525/as.2002.42.4.550.; Friend (2003), page 107-109, 113.