ABUNDANCE RATIO OF HELIUM TO HYDROGEN IN EXTRAGALACTIC NEBULAE - SPINRAD, H; PEIMBERT, M (UNAM, Inst Astron, 1970)
ASTROPHYS J
Keywords: ABUNDANCE, RATIO, HELIUM, HYDROGEN, EXTRAGALACTIC NEBULAE; ASTRONOMIA Y ASTROFISICA; COSMOLOGIA Y COSMOGONIA; ESTRELLAS