Spectral survey of Case emission–line galaxies with the 6 m Russian telescopeA. V. Ugryumov, S. A. Pustilnik, V. A. Lipovetsky, Yu. I. Izotov and G. RichterAstron. Astrophys. Suppl. Ser., 131 2 (1998) 295-302DOI: https://doi.org/10.1051/aas:1998269