Recommended introductory books for understanding detonation in engines include "Gaseous Detonations: Their Nature, Effects and Control" by M.A. Nettleton and "Internal Combustion Engine Fundamentals" by John Heywood, which is highly regarded in the field. The Wikipedia page on engine knocking serves as a useful starting point for basic concepts. Additionally, "IC Engine" by M.L. Mathur and R.P. Sharma is suggested for further insights. The discussion emphasizes the importance of foundational knowledge in the subject of engine detonation. These resources provide a solid basis for understanding the complexities of engine knock and detonation phenomena.