Recommendations for books on mathematical inequalities include several notable titles. A classic reference is "Inequalities" by Hardy, Littlewood, and Pólya, which covers fundamental concepts like Jensen's inequality and the Arithmetic Mean-Geometric Mean inequality. "Inequalities: A Mathematical Olympiad Approach" is praised for its clear writing and engaging content. Another suggested title is "The Cauchy-Schwarz Master Class," which is highly regarded for its thorough exploration of inequalities. Additionally, the book by Beckenbach and Bellaman is mentioned as a potential choice for further reading.