Japan Report. Vol. 5. Japan Information Center, Consulate General of Japan. 1959. p. 12-PA2.
Nathaniel B. Thyer (2018). "The Factions". In Robert Pekkanen (ed.). Critical Readings on the Liberal Democratic Party in Japan. Vol. 2. Leiden; Boston, MA: Brill. p. 687. ISBN978-90-04-38053-0.