Cornell Chronicle - "Neutron stars can be more massive, while black holes are more rare, Arecibo Observatory finds", 1/17/2008, Box: 54, Folder: 372. Arecibo Ionospheric Observatory records, 53-7-3581. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/285023 Accessed April 01, 2026.