Cotton, W. D.; Condon, J. J.; Arbizzani, E. (December 1999), "Arcsecond Positions of UGC Galaxies", The Astrophysical Journal Supplement Series, 125 (2): 409–412, Bibcode:1999ApJS..125..409C, doi:10.1086/313286.
Huchra, John P.; Geller, Margaret J.; Corwin, Harold G. Jr. (August 1995). "The CfA Redshift Survey: Data for the NGP +36 Zone". Astrophysical Journal Supplement. 99: 391. Bibcode:1995ApJS...99..391H. doi:10.1086/192191.
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Cotton, W. D.; Condon, J. J.; Arbizzani, E. (December 1999), "Arcsecond Positions of UGC Galaxies", The Astrophysical Journal Supplement Series, 125 (2): 409–412, Bibcode:1999ApJS..125..409C, doi:10.1086/313286.
Huchra, John P.; Geller, Margaret J.; Corwin, Harold G. Jr. (August 1995). "The CfA Redshift Survey: Data for the NGP +36 Zone". Astrophysical Journal Supplement. 99: 391. Bibcode:1995ApJS...99..391H. doi:10.1086/192191.