1.Introduction.- 2.Mathematical Preliminaries.- 3.Physical Backgrounds.- 4.Equations with one Space Variable in Cartesian Coordinates.- 5.Equations with one Space Variable in Polar Coordinates.- 6.Equations with one Space Variable in Spherical Coordinates.- 7.Equations with two Space Variables in Cartesian Coordinates.- 8.Equations in Polar Coordinates.- 9.Axisymmetric equations in Cylindrical Coordinates.- 10.Equations with three Space Variables...