Heuveline, Patrick (1998). "'Between One and Three Million': Towards the Demographic Reconstruction of a Decade of Cambodian History (1970–79)". Population Studies. 52 (1): 49–65. doi:10.1080/0032472031000150176. JSTOR 2584763. PMID11619945. pp. 49-65.
Dmitry Mosyakov, “The Khmer Rouge and the Vietnamese Communists: A History of Their Relations as Told in the Soviet Archives,” in Susan E. Cook, ed., Genocide in Cambodia and Rwanda (Yale Genocide Studies Program Monograph Series No. 1, 2004), p54ff. （
オンライン版） 『1970年4月から5月にかけて、ヌオン・チアによる要請を受け、多くの北ベトナム軍部隊がカンボジアに侵入した。Nguyen Co Thachは「ヌオン・チアからの要請を受け、我々は10日でカンボジアの5州を解放した」と回想している』 "In April–May 1970, many North Vietnamese forces entered Cambodia in response to the call for help addressed to Vietnam not by Pol Pot, but by his deputy Nuon Chea. Nguyen Co Thach recalls: "Nuon Chea has asked for help and we have liberated five provinces of Cambodia in ten days.""
