1 Spherical Harmonics.- 2 Convolution and Spherical Harmonic Expansion.- 3 Littlewood-Paley Theory and Multiplier Theorem.- 4 Approximation on the Sphere.- 5 Weighted Polynomial Inequalities.- 6 Cubature Formulas on Spheres.- 7 Harmonic Analysis Associated to Reflection Groups.- 8 Boundedness of Projection Operator and Ces?ro Means.- 9 Projection Operators and Ces?ro Means in L p Spaces.- 10 Weighted Best Approximation...