Editing Ring Nebula (section)

==References==
{{reflist|30em|refs=
<ref name=coe2007>{{Cite book | first1=Steven R. | last1=Coe | title=Nebulae and how to observe them | series=Astronomers' observing guides | publisher=Springer | date=2007 | isbn=978-1-84628-482-3 | page=111 | url=https://books.google.com/books?id=roXyxpcc9MsC&pg=PA111}}</ref>

<ref name=crossen_rhemann2004>{{Cite book | first1=Craig | last1=Crossen | first2=Gerald | last2=Rhemann | title=Sky Vistas: Astronomy for Binoculars and Richest-field Telescopes | publisher=Springer | date=2004 | isbn=978-3-211-00851-5 | page=[https://archive.org/details/springer_10.1007-978-3-7091-0626-6/page/n310 261] | url=https://archive.org/details/springer_10.1007-978-3-7091-0626-6}}</ref>

<ref name=steinicke2010>{{Cite book | first1=Wolfgang | last1=Steinicke | title=Observing and Cataloguing Nebulae and Star Clusters: From Herschel to Dreyer's New General Catalogue | publisher=Cambridge University Press | date=2010 | isbn=978-0-521-19267-5 | pages=42–43 | url=https://books.google.com/books?id=wyWjVWYWoO8C&pg=PA43}}</ref>
}}