1. Introduction.- 2. Analytical Methods for the Calculation of Quasienergy States (QS) of Quantum Systems.- 2.1 Interaction of Quantum Systems with a Nonstationary Field.- 2.2 Perturbation Theory for QSs of Degenerate Quantum Systems.- 2.2.1 Calculation of the QSs as a Stationary Problem.- 2.2.2 Perturbation Theory.- 2.3 High-Frequency or Very Intense Nonstationary Fields.- 2.3.1 Calculation of the QSs as a Stationary Problem.- 2.3.2 Perturbation Theory.- 2.3.3 Generalizations.- 3. Action of One-Dimensional Quasimonochromatic Electric Fields (QEF) on Coulomb Emitters.- 3.1 Splitting of Hydrogen-like Spectral Lines in a Single-Mode QEF.- 3.1.1 Analytical Investigation.- 3.1.2 Numerical Calculations. Oscillatory Behavior of Halfwidths and Intensities.- 3.1.3 Doppler Broadening. Formal Analogy with Thomson Scattering in the Presence of QEFs.- 3.2 Splitting of Hydrogen-like Spectral Lines in a Multimode QEF.- 3.2.1 Analytical Investigation for the Number of Modes Approaching Infinity, and Equal to 2.- 3.2.2 Numerical Calculations.- 3.3 Impact Broadening of Hydrogen-like Spectral Lines.- 3.3.1 Modifications of Impact Broadening Due to QEF.- 3.3.2 Modification of QEF-induced Line Splitting Due to Impact Broadening.- 3.4 Frequency-integrated Radiative Characteristics of Hydrogen-like Emitters Interacting with a Resonant Laser Field and a Low-Frequency QEF.- 3.4.1 Resonant Multiquantum Interaction.- 3.4.2 Non-Degenerate Case.- 3.4.3 Degenerate Case.- 3.4.4 Applications of the Results.- 4. Action of Multidimensional Dynamic Electric Fields on Coulomb Emitters.- 4.1 Splitting of Hydrogen-like Spectral Lines in a Plane Polarized QEF.- 4.1.1 Analytical Results for a Circularly Polarized Field.- 4.1.2 Multiquantum Dynamic Resonance in an Elliptically Polarized Field.- 4.1.3 Elliptically Polarized Fields in the High-Frequency Limit.- 4.1.4 Measurements of Elliptically Polarized Field Parameters.- 4.1.5 Analytical Investigation of Two-Dimensional Multimode QEFs.- 4.2 Joint Action of QEF and Quasistatic EF on Hydrogen-like Spectral Lines.- 4.2.1 Dynamic Resonance.- 4.2.2 Hydrogen-like Lines at a Multiquantum Dynamic Resonance and Away from the Resonance.- 4.2.3 The L? Spectral Line with Detuning from Resonance.- 4.2.4 Dips in Hydrogen Spectral Lines Resulting from the Resonance Effects.- 4.2.5 Intra-Stark Spectroscopy. Diagnostic Recommendations.- 4.3 Hydrogen-like Spectral Lines in a High-Frequency or Strong QEF with a Quasistatic EF.- 4.3.1 Calculation of Quasienergy States.- 4.3.2 Calculations of the L?, L? and H? Line Profiles.- 4.3.3 Further Generalizations for the Action of a Static Magnetic Field.- 5. Action of a One-Dimensional QEF on Non-Coulomb Emitters.- 5.1 Satellites of Dipole-Forbidden Spectral Lines Caused by a Nonresonant Action of QEFs (Three-Level Scheme).- 5.1.1 Dirac Perturbation Theory. Baranger-Mozer Method for Measurements of QEF Parameters.- 5.1.2 Adiabatic Theory of Satellites and Quasilocal Method for Measurements of QEF Parameters.- 5.1.3 Polarization of Satellites.- 5.1.4 Strong Asymmetry of Satellite Distribution in Very Intense QEFs.- 5.1.5 Modification of Helium-like Ion Satellites Caused by Mixing of Singlet and Triplet Terms.- 5.1.6 Satellites in a Stochastic QEF.- 5.2 Satellites of Dipole-Forbidden Spectral Lines in Resonant QEFs. Three-Level Scheme.- 5.2.1 Multiquantum Resonance in a Two-Level Subsystem.- 5.2.2 Spectrum of Spontaneous Transitions to a Third Level in a Multiquantum Resonance.- 5.3 Satellites of Dipole-Forbidden Spectral Lines in More Complicated (Four-Level) Systems.- 5.3.1 QSs of a Three-Level Subsystem in a High-Frequency or Intense Field.- 5.3.2 Radiative Transitions from the States 2P1/2, 2S1/2, 2P3/2 of a Hydrogen-like Ion in a High-Frequency or Intense Field.- 5.4 Electron Oscillatory Shift in Plasmas Interacting with a Powerful Coherent Radiation.- 5.4.1 Calculation in the Rectilinear Trajectories Approximation.- 5.4.2 Calculations Including Curved Trajectories.- 5.4.3 Discussion.- 5.5 Action of QEFs on Diatomic Polar Molecules.- 5.5.1 Satellites in Vibrational-Rotational Spectra.- 5.5.2 Ultra-sensitive Laser Induced Fluorescence Measurements of Weak QEFs in Low-Temperature Plasmas.- 5.6 Frequency-Integrated Radiative Characteristics of Non-Coloumb Emitters Interacting with a Resonant Laser Field and Low-Frequency QEF.- 6. Non-Coulomb Emitters Under Multidimensional Dynamic EFs (Elliptically Polarized QEFs; Quasistatic EF plus QEF).- 6.1 Satellites of Dipole-Forbidden Spectral Lines Caused by an Elliptically Polarized QEF.- 6.1.1 Three-Level Scheme, Nonresonant QEF.- 6.1.2 Three-Level Scheme, Resonant QEF.- 6.1.3 Four-Level Scheme.- 6.2 Joint Action of QEF and Intraplasmic Quasistatic EF on Non-Coulomb Emitters.- 6.2.1 Strong Influence of a Quasistatic EF on Satellites of Dipole-Forbidden Lines.- 6.2.2 Intra-Stark Spectroscopy.- 6.2.3 Joint Action of a Quasistatic EF and a High-Frequency QEF on a Hydrogen-like Ion. Fine Structure and Lamb Shift. Local Measurements of Amplitude Angular Distributions of Low-Frequency Plasma Turbulence.- 6.3 Shift of Spectral Lines of Diatomic Polar Molecules in an Elliptically Polarized QEF.- 7. Applications of the Theory to Experimental Plasma Diagnostics.- 7.1 Preliminary Remarks.- 7.2 QEFs in ?-Pinches.- 7.2.1 QEFs Under a Magnetic Field Annihilation.- 7.2.2 QEFs Under a Rapid Compression of a ?-Pinch Plasma.- 7.3 QEFs in a Z-Pinch.- 7.4 New Features of Intra-Stark Spectroscopy Caused by a High Density of Plasmas.- 7.5 QEFs in Tokamaks.- 7.5.1 Intense EFs in the Edge Plasma of the T-10 Tokamak.- 7.5.2 Novel Spectroscopic Diagnostics of EFs in Tokamaks.- 7.6 QEFs in Plasmas Interacting with a Strong Microwave Field.- 7.6.1 Technique Utilizing Hydrogen or Deuterium Lines.- 7.6.2 Quasilocal Measurements Technique Utilizing Lines of Non-Coulomb Emitters.- 7.6.3 Techniques of Local Laser Fluorescence Diagnostics.- Appendices.- D Generalized QSs of a Hydrogen Atom in a Bichromatic EF.- E Influence of Bound Electrons on the Frequency and Damping of Langmuir Oscillations.- References.