Preface and historical note -- Laplace-Beltrami operator -- Harmonic functions -- Quasiharmonic functions -- Bounded biharmonic functions -- Dirichlet finite biharmonic functions -- Bounded dirichlet finite biharmonic functions -- Harmonic, quasiharmonic, and biharmonic degeneracies -- Riesz representation of biharmonic functions -- Biharmonic Greenโ{128}{153}s function ? -- Biharmonic Greenโ{128}{153}s function ?: Definition and existence -- Relation of O ? N to other null classes -- Hadamardโ{128}{153}s conjecture on the Greenโ{128}{153}s function of a clamped plate