Absolute intensities of the emission lines in faint planetary nebulae visible in the direction to the galactic centre. Vorontsov-Vel'Yaminov, B. A. ; Kostyakova, E. B. ; Dokuchaeva, O. D. ; Arkhipova, V. P. ; Kharadze, E. K. ; Bartaya, R. A. ; Kulidgeanishvili, G. Abstract Publication: Astronomicheskij Tsirkulyar Pub Date: 1970 Bibcode: 1970ATsir.563....4V