Books I've appreciated and learned from on this topic:
The Law of the Somalis (about a modern-day decentralised legal system that refuses to die)
https://www.explorersfoundation.org/archive/139t2-somalis-ch1.pdf
The Enterprise of Law: Justice without the State
https://mises.org/library/books?book_type=All&book_type=All&author=All&topic=197&austrian_school=All