The exciton mechanism of high critical temperature superconductivity in copper oxides was initially proposed by Prof. J. Bardeen. His insight is largely shared by another luminary in superconductivity, Prof. V. L. Ginzburg. The Chief Editor of the book, was motivated by their insights to give a geometrical explanation to the excitonic Coulomb interaction and has developed a unique formalism to understand and predict physical properties of high Tc superconductors. This work is supported by increasingly strong evidences for electron-hole interactions in p-type cuprates. The presence of electrons in hole-doped cuprates are revealed by the works of the Editors and many others, including the late Prof. L. P. Gor'kov. The book also tries to understand the interlayer Coulomb (ILC) pairing model by the excitonic Coulomb interaction.