We will never get better at COIN, until we first get better at our understanding of insurgency.
Revolution, internal to a single system and non-war; resistance, the continuation of warfare by an undefeated populace in a clash between systems - and the fusion of the two when one goes abroad and attempts to create and secure a government more pleasing to that creator than to so many forced to live under it.

These are indeed great references, particularly when read for the facts they gather, organize and offer - and not for conclusions too often overly colored by the bias of our own culture, perspective and doctrine.

Highly recommended these as a cornerstone of references for all who study, think about, and engage in some way in these conflicts.