3. The Creation of Wave Mechanics: Scientific Exchange with Plank and Einstein; First Steps Toward the Hydrogen Equation; The Nonrelativistic Hydrogen Equation; Sources of Undulatory Mechanics; Foundations of Undulatory Mechanics. 4. Early Response and Applications: The Scheme Starts to Work; Early Response to Wave Mechanics; Formal Equivalence of Wave Mechanics and Matrix Mechanics; Application and Extensions; Towards an Undulatory Interpretation of Atomic Phenomena.

Comments by distinguished physicists on "The Historical Development of Quantum Theory": "the most definitive work undertaken by anyone on this vast and most important development in the history of physics. Jagdish Mehra, trained in theoretical physics under Pauli, Heisenberg, and Dirac, pursued the vision of his youth to write about the historical and conceptual development of quantum theory in the 20th century. This series of books on the HDQT has thus become the most authentic and permanent source of our knowledge of how quantum theory, its extensions and applications developed. My heartfelt congratulations." -Hans A. Bethe, Nobel Laureate "A thrilling and magnificent achievement!" -Subrahmanyan Chandrasekhar, FRS, Nobel Laureate "capture(s) precisely, accurately, and thoroughly the very essence and all the fundamental details of the theory, and that is a remarkable achievement. I have greatly enjoyed reading these books and learned so many new things from them. This series of books will remain a permanent source of knowledge about the creation and development of quantum theory. Congratulations!" -Paul A. Dirac, FRS, Nobel Laureate "The wealth and accuracy of detail in he Historical Development of Quantum Theory'are breathtaking." -Richard P. Feynman, Nobel Laureate