The first two parts of this review, which include general information concerning electronic spectra and levels and comprehensive information concerning energy region between the dissociation threshold and the near–ultraviolet (the Huggins bands) were published in the journals Atmospheric and Oceanic Optics, Nos. 5 and 8, 1993. In this paper they are referred to as Parts I and II. For convenience and continuity of this paper, I first repeate the references of Parts I and II and then add the new references.