Pike, Douglas (1989). "National Security". In Cima, Ronald J. (ed.). Vietnam: A Country Study(PDF). Area Handbook. Washington, D.C.: Library of Congress. p. 256. LCCN88600482. Retrieved 5 July 2022.
marines.mil
Pike, Douglas (1989). "National Security". In Cima, Ronald J. (ed.). Vietnam: A Country Study(PDF). Area Handbook. Washington, D.C.: Library of Congress. p. 256. LCCN88600482. Retrieved 5 July 2022.