J. Allen Hynek (English Wikipedia)

Clark, Jerome (1998). The UFO Book: Encyclopedia of the Extraterrestrial. Visible Ink. pp. 305. ISBN 1-57859-029-9. Emphasis in source.
Vallee, Jacques (1992). Forbidden Science: Journals 1957-1969. Berkeley, CA: North Atlantic Books. pp.302-303. ISBN 1-55643-125-2. (Digitized and archived by Internet Archive in 2015.) Archived version retrieved March 16, 2024.

badufos.blogspot.com

Sheaffer, Robert (September 17, 2020). "Book Review: 'The Close Encounters Man' by Mark O'Connell". Bad UFOs. Archived from the original on February 26, 2024.

cufos.org

"The J. Allen Hynek Center for UFO Studies". Retrieved February 10, 2008.

debunker.com

Michael Tenszen (July 5, 1982). "Close Encounter Still up in Air for UFO Expert" (PDF). The Globe and Mail. Retrieved October 19, 2011.
Sheaffer, Robert. "Historical Documents Pertaining to UFOlogy". The Debunker's Domain. Archived from the original on February 5, 2024.

doi.org

Gamow, G.; Hynek, J. A. (March 1, 1945). "A New Theory by C. F. Von Weizsacker of the Origin of the Planetary System". The Astrophysical Journal. 101: 249. Bibcode:1945ApJ...101..249G. doi:10.1086/144711.

gpposner.com

Sheaffer, Robert (1979). "Review: Proceedings of the 1976 CUFOS Conference" (PDF). Skeptical Inquirer. 3 (4): 58–61. Archived (PDF) from the original on April 1, 2024.
Fraknoi, Andrew. Letter to Science Digest. September 14, 1981. Archived from the original on March 28, 2024.
Hendry, Allan (1979). The UFO Handbook: A Guide to Investigating, Evaluating and Reporting UFO Sightings. Doubleday. p. 205. ISBN 9780385143486. Archived from the original on March 31, 2024

harvard.edu

ui.adsabs.harvard.edu

Gamow, G.; Hynek, J. A. (March 1, 1945). "A New Theory by C. F. Von Weizsacker of the Origin of the Planetary System". The Astrophysical Journal. 101: 249. Bibcode:1945ApJ...101..249G. doi:10.1086/144711.

history.com

Daugherty, Greg. "Meet J. Allen Hynek, the Astronomer Who First Classified UFO 'Close Encounters'". History.com. Retrieved May 28, 2019.

ncas.org

files.ncas.org

Symposium on Unidentified Flying Objects: Hearings before the Committee on Science and Astronautics, U.S. House of Representatives. Washington: U.S. Government Printing Office. July 29, 1968. p. 4. Archived from the original on April 16, 2011.

newspapers.com

"Boys Say They Watched 'UFO.'". The Times Herald. January 10, 1967. p. 1. Archived from the original on March 28, 2024.

nicap.org

"Chapter Three: The Report on Unidentified Flying Objects". NICAP. Retrieved August 27, 2007.

northwestern.edu

findingaids.library.northwestern.edu

"J. Allen Hynek (1910–1986) Papers". Archival and Manuscript Collections. Northwestern University Library. Retrieved May 9, 2016.

nytimes.com

Kriss, Gary (April 17, 1983). "On the Trail of UFOs". The New York Times. Archived from the original on June 20, 2021.

skepticalinquirer.org

Sheaffer, Robert (1978). "Review: The Hynek UFO Report". Skeptical Inquirer. 3 (2): 64–67. Archived from the original on July 6, 2020.
Sheaffer, Robert (1977). "Book Review: The Edge of Reality…" (PDF). The Zetetic. 1 (2): 72–80. Archived (PDF) from the original on January 8, 2022.
Franch, John (2013). "The Secret Life of J. Allen Hynek". Skeptical Inquirer. 37 (1). Archived from the original on November 22, 2020.

thesaucersthattimeforgot.blogspot.com

Collins, Curt (October 21, 2021). “Dr. Hynek and the UFO Photo Investigation of 1967.” Archived from the original on March 27, 2024.

ufoevidence.org

"Dr. J. Allen Hynek Speaking at the United Nations, Nov. 27th 1978". Retrieved August 27, 2007.

web.archive.org

Starlight Fluctuation Studies – The Defense Technical Information Center
Kriss, Gary (April 17, 1983). "On the Trail of UFOs". The New York Times. Archived from the original on June 20, 2021.
Symposium on Unidentified Flying Objects: Hearings before the Committee on Science and Astronautics, U.S. House of Representatives. Washington: U.S. Government Printing Office. July 29, 1968. p. 4. Archived from the original on April 16, 2011.
Sheaffer, Robert (September 17, 2020). "Book Review: 'The Close Encounters Man' by Mark O'Connell". Bad UFOs. Archived from the original on February 26, 2024.
Sheaffer, Robert (1978). "Review: The Hynek UFO Report". Skeptical Inquirer. 3 (2): 64–67. Archived from the original on July 6, 2020.
Sheaffer, Robert. "Historical Documents Pertaining to UFOlogy". The Debunker's Domain. Archived from the original on February 5, 2024.
Sheaffer, Robert (1979). "Review: Proceedings of the 1976 CUFOS Conference" (PDF). Skeptical Inquirer. 3 (4): 58–61. Archived (PDF) from the original on April 1, 2024.
Sheaffer, Robert (1977). "Book Review: The Edge of Reality…" (PDF). The Zetetic. 1 (2): 72–80. Archived (PDF) from the original on January 8, 2022.
Fraknoi, Andrew. Letter to Science Digest. September 14, 1981. Archived from the original on March 28, 2024.
Collins, Curt (October 21, 2021). “Dr. Hynek and the UFO Photo Investigation of 1967.” Archived from the original on March 27, 2024.
Hendry, Allan (1979). The UFO Handbook: A Guide to Investigating, Evaluating and Reporting UFO Sightings. Doubleday. p. 205. ISBN 9780385143486. Archived from the original on March 31, 2024
"Boys Say They Watched 'UFO.'". The Times Herald. January 10, 1967. p. 1. Archived from the original on March 28, 2024.
Franch, John (2013). "The Secret Life of J. Allen Hynek". Skeptical Inquirer. 37 (1). Archived from the original on November 22, 2020.