The Case for Secession, Radical Decentralisation, and Smaller Polities

Further reading:

Breaking Away: The Case for Secession, Radical Decentralization, and Smaller Polities by Ryan McMaken

Secession, State, and Liberty edited by David Gordon

On Centralization and Secession by Hans-Hermann Hoppe (Chapter 5 in Democracy: The God That Failed; for an online pdf see here)

The Nationalities Question by Murray N. Rothbard (pp. 225-235 in The Irrepressible Rothbard)

Escape from Rome: The Failure of Empire and the Road to Prosperity by Walter Scheidel

The European Miracle by Ralph Raico

Conceived in Liberty: The Medieval Communes of Europe by Guglielmo Piombini

The Myth of National Defense: Essays on the Theory and History of Security Production edited by Hans-Hermann Hoppe

The Power of Nations: Measuring What Matters by Michael Beckley

No, the Chinese Won't Invade America If Secessionists Succeed by Ryan McMaken

Why No State Needs Thousands of Nuclear Warheads by Ryan McMaken