: Marine Corps Gazette via the Homeland Security Digital Library .
by Antulio J. Echevarria II.
by Major Robert B. Polk.
The definitive starting point for this topic is the 1989 paper by and others, which first defined the concept. 📄 The Foundational Text 4th Generation Warfare Free Download
To get a balanced view, you should read the main scholarly critiques that challenge the "Generations" theory: : Marine Corps Gazette via the Homeland Security
Often cited as the most comprehensive book on the subject; available for borrowing or viewing on Internet Archive. 4th Generation Warfare Free Download