Additional Sources
18 - James M. Buchanan

Most Important Work
The Calculus of Consent (with Gordon Tullock, 1962)
https://www.econlib.org/library/Buchanan/buchCv3.html
The Limits of Liberty: Between Anarchy and Leviathan (1975)
https://www.econlib.org/library/Buchanan/buchCv7.html
More about...
Video
Interview in two parts: A Conversation with James M. Buchanan
https://www.econlib.org/archives/2013/10/james_buchanan_conversation.html
Book as pdf
The Essential James Buchanan (published by Fraser Institute)
https://www.fraserinstitute.org/sites/default/files/essential-james-buchanan.pdf