Fluorescence and laser activity of some pyrazinyl Schiff-base derivatives M.M.F. Sabry, E.M. Ebeid, Y.M. Issa and S.A. El-Daly J. Chim. Phys., 86 (1989) 2163-2172 Published online: 29 May 2017 DOI: 10.1051/jcp/1989862163