Townshend, Charles (2011). Terrorism : a very short introduction 2nd ed. Oxford [u.a.]: Oxford Univ. Press. p. 116. ISBN9780199603947. Consultado em 7 de agosto de 2012. (... enough Sarin in Aum's possession to kill over 4 million people).
National Police Agency (Japão) (2009), "The White Paper on Police 2009 (平成21年警察白書,Heisei Nijūichi nen Keisatsu Hakusyo?)), GYOSEI Corporation, English p. 160.