NGC 6989 (Polish Wikipedia)

Analysis of information sources in references of the Wikipedia article "NGC 6989" in Polish language version.

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8,256^th place

1haroldcorwin.net

low place

low place

cseligman.com

Courtney Seligman: NGC 6989. Celestial Atlas. [dostęp 2014-09-18]. (ang.).

haroldcorwin.net

Harold G. Corwin Jr.: NGC 6989. [w:] Notes on the NGC objects, particularly those missing, misidentified, or otherwise unusual [on-line]. 2017-06-20. [dostęp 2017-10-23]. (ang.).

usp.br

astro.iag.usp.br

Wilton Dias et al.: Catalog of Optically Visible Open Clusters and Candidates – List of Removed Clusters. Departamento de Astronomia, 2014-05-24. [dostęp 2017-10-23].