'Chemical abundances in H II regions and their implications -- Retrospective on: M. Peimbert & R. Costero, Boletin de los Observatorios de Tonantzintla y Tacubaya, Vol. 5, 3, 1969'

'Chemical Compositions, Physical & Structure of High- Excitation Planetary Nebulae'

'Chemical structure' in the red giant Hertzsprung-Russell diagram, and the age of the galactic disk

'Chemical' low frequency waveguide in the upper ionosphere

'Clean and Restore' technique applied to observations from the 'Westerbork Synthesis Radiotelescope' and from the 'Northern Cross radiotelescope'

'Closed' and 'open' solar wind streams

'Cold fusion': formation of molecules in interstellar plasmas

'Cold' material in non-thermal sources

'Collisionless electron heat conduction' and the polytrope law

'Comet' eyepiece problems.

'Computing' as Information Compression by Multiple Alignment, Unification and Search

'Congruent Partitions' of Polygons - a Short Introduction

'Conserved' quantities for isolated gravitational systems

'Continuum' in the emission of an artificial aurora

'Copernicus' observations of extragalactic X-ray sources

'Coronae' of rotating interstellar clouds

'Correlatation of petrology and natural magnetic polarity in Columbia Plateau basalts' by R. L. Wilson and N. D. Watkins

'Correlations between λ4278 optical emissions and VlF wave events observed at L~4 in the Antarctic'

'Crossing' method for studying the turbulence in solar and stellar atmospheres. I - Application to the sun

'Cusp' solutions in Gauss-Bonnet gravity