Introduction; Theoretical Aspects of Molecular Rotation; Microwave Transitions - Line Intensities and Shapes; Diatomic Molecules; Linear Polyatomic Molecules; Symmetric-Top Molecules; Asymmetric-Top Molecules; The Distortable Rotor; Nuclear Hyperfine Structure in Molecular Rotational Spectra; Effects of Applied Electric Fields; Effects of Applied Magnetic Fields; Internal Motions; Derivation of Molecular Structures; Quadrupole Couplings, Dipole Moments, and the Chemical Bond; Irreducible Tensor Methods for Calculation of Complex Spectra; Appendixes; Author Index; Subject Index.