NGC 2277National Aeronautics and Space Administration / Infrared Processing and Analysis Center(英语:Infrared Processing and Analysis Center). [5 August 2017].
NGC 4634National Aeronautics and Space Administration / Infrared Processing and Analysis Center(英语:Infrared Processing and Analysis Center). [13 February 2017]
阿普256Extragalactic Database. National Aeronautics and Space Administration / Infrared Processing and Analysis Center. [29 March 2018]. (原始内容存档于2019-07-13). NED
NGC 3501National Aeronautics and Space Administration / Infrared Processing and Analysis Center(英语:Infrared Processing and Analysis Center). [14 February 2017]
NGC 3697National Aeronautics and Space Administration / Infrared Processing and Analysis Center(英语:Infrared Processing and Analysis Center). [9 November 2017]