Smith, Adam. (1776) An Inquiry into the Nature And Causes of the Wealth of Nations Book 5. Chapter 1. Part 1.[1]Archived 2007-09-27 at the Wayback Machine
Mitchel A. Sollenberger (2015). "President and Congressional Relations: An Evolution of Military Appointments". In Colton C. Campbell & David P. Auerswald (ed.). Congress and Civil-Military Relations. Georgetown University Press. pp. 29–31. ISBN978-1626161801.
Smith, Adam. (1776) An Inquiry into the Nature And Causes of the Wealth of Nations Book 5. Chapter 1. Part 1.[1]Archived 2007-09-27 at the Wayback Machine