Liên quan Messier 81 Messier 87 Messier 102 Messier 15 Messier 110 Messier 86 Messier 88 Messier 80 Messier 100 Messier 85
Tài liệu tham khảo WikiPedia: Messier_81 http://ned.ipac.caltech.edu/cgi-bin/objsearch?objn... http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=... //arxiv.org/abs/astro-ph/0606440 //doi.org/10.1086%2F516636 https://ui.adsabs.harvard.edu/abs/2007ApJS..173..1... https://id.loc.gov/authorities/subjects/sh93008380 https://www.wikidata.org/wiki/Q14024#identifiers
