ASTRONOMY AND ASTROPHYSICS A group of galaxies around the giant spiral NGC 6946 I D Karachentsev,M E Sharina,W K Huchtmeiermag(2013)引用 23|浏览1暂无评分AI 理解论文溯源树样例生成溯源树,研究论文发展脉络Chat Paper正在生成论文摘要