Tham khảo Người_ngoài_hành_tinh_Xám

  1. ↑ Bryan, C. D. B. (1995). Close Encounters of the Fourth Kind: Alien Abduction, UFOs, and the Conference at M.I.T. . NY, US: Alfred A. Knopf, Inc. ISBN 978-0-679-42975-3. OCLC 32390030 – qua Internet Archive. This work is based on the author's experience of a five-day UFO conference at Massachusetts Institute of Technology.
  2. ↑ Cannon, Martin (tháng 10 năm 1995). The Controllers. ISBN 0-922915-32-6.
  3. ↑ Constantine, Alex (1995). Psychic Dictatorship in the U.S.A. Feral House. ISBN 0-922915-28-8.
  4. 1 2 Jacobs, David M. "Aliens and Hybrids." In: Pritchard, Andrea & Pritchard, David E. & Mack, John E. & Kasey, Pam & Yapp, Claudia. Alien Discussions: Proceedings of the Abduction Study Conference. Cambridge: North Cambridge Press. Pp. 86–90. ISBN 9780964491700
  5. ↑ Haight, Gordon (1958). “Nineteenth-Century Fiction, vol. 12, no. 4”. Nineteenth-Century Fiction. JSTOR: University of California Press. 12 (4): 324. JSTOR 3044429.
  6. ↑ Kottmeyer, Martin. “Entirely Unpredisposed”. www.debunker.com. Truy cập ngày 19 tháng 9 năm 2008. (originally published in Magonia magazine, January 1990).