Thực đơn
NGC_57 Xem thêmThực đơn
NGC_57 Xem thêmLiên quan
Tài liệu tham khảo
WikiPedia: NGC_57 http://cseligman.com/text/atlas/ngc0a.htm#57 http://nedwww.ipac.caltech.edu/cgi-bin/nph-objsear... http://www.k-itagaki.jp/images/psn57.jpg http://www.rochesterastronomy.org/snimages/ http://spider.seds.org/ngc/revngcic.cgi?NGC57 http://server1.wikisky.org/starview?object=NGC+57 http://www.wikisky.org/?object=NGC+57 http://www.wikisky.org/?object=NGC+57&img_source=D... http://www.wikisky.org/?object=NGC+57&img_source=H... http://www.wikisky.org/?object=NGC+57&img_source=I...