The prince actually wrote a book that seems to be heavily inspired by "The Sovereign Individual". It's called The State in the Third Millennium.

He stated that government should be limited to a small set of tasks and abilities, writing that people "have to free the state from all the unnecessary tasks and burdens with which it has been loaded during the last hundred years, which have distracted it from its two main tasks: maintenance of the rule of law and foreign policy."

https://www.fixthemoney.net/p/why-liechtenstein-is-adopting-bitcoin