Reviews of topical problems

M.S. Marinov “Relativistic strings and dual models of the strong interactions” Sov. Phys. Usp. 20 179–208 (1977)

N.G. Basov, E.M. Belenov, V.A. Isakov, E.P. Markin, A.N. Oraevskii, V.I. Romanenko “New methods of isotope separation” Sov. Phys. Usp. 20 209–225 (1977)

V.B. Shikin “Mobility of charges in liquid, solid, and dense gaseous helium” Sov. Phys. Usp. 20 226–248 (1977)

R.G. Mints, A.L. Rakhmanov “Magnetic instabilities in hard superconductors” Sov. Phys. Usp. 20 249–263 (1977)

Methodological notes

M.A. Miller, Yu.M. Sorokin, N.S. Stepanov “Covariance of Maxwell equations and comparison of electrodynamic systems” Sov. Phys. Usp. 20 264–272 (1977)

Meetings and conferences

M.I. Kudryavtsev, A.S. Melioranskii, I.A. Savenko “Bursts and Sources of Hard X-Radiation.” Sov. Phys. Usp. 20 273–275 (1977)

V.L. Ginzburg, L.M. Ozernoi “The Nature of Quasars and the Active Nuclei of Galaxies” Sov. Phys. Usp. 20 275–275 (1977)

I.L. Fabelinskii, V.S. Starunov, A.K. Atakhodzhaev, T.M. Utarova, G.I. Kolesnikov “Narrowing of Optical Depolarization-Scattering Spectra Near the Critical Separation Point of Solutions” Sov. Phys. Usp. 20 275–276 (1977)

V.G. Kurt “The Motion of the Sun in the Interstellar Medium” Sov. Phys. Usp. 20 276–277 (1977)