Cornell Chronicle - "It's the 25th Anniversary of Earth's first (and only) attempt to phone E.T." (Bill Steele), 11/11/99, Box: 54, Folder: 274. Arecibo Ionospheric Observatory records, 53-7-3581. Division of Rare and Manuscript Collections. https://archives.library.cornell.edu/repositories/2/archival_objects/284903 Accessed April 13, 2026.