Đọc thêm Giả_thuyết_UFO_tâm_lý_xã_hội

Tài liệu tham khảo

WikiPedia: Giả_thuyết_UFO_tâm_lý_xã_hội http://magonia.haaan.com/2009/doubt/ https://web.archive.org/web/20130819033323/http://... http://magonia.haaan.com/2010/questioning-the-real... http://magonia.haaan.com/2009/mind/ https://web.archive.org/web/20130819002218/http://... http://magonia.haaan.com/2009/decade/ https://web.archive.org/web/20130819014602/http://... http://magonia.haaan.com/1981/why-have-all-the-ufo... http://magonia.haaan.com/2010/enginestoppers/ https://web.archive.org/web/20131001033541/http://...