"From 1947 until 17 December 1969, the United States Air Force actively investigated reports and sightings of unidentified flying objects - UFOs, under a program called Project Blue Book. Project Blue Book investigated 12,618 UFO sightings and 701 of those sightings remained unidentified. Many UFO researchers feel that the investigations of the UFO sightings were unprofessional and unscientific. The program used poor research methods and researchers were too eager to label a mysterious sighting as "identified" phenomena. Individual researchers and UFO organisations believe that members of Project Blue Book were pressured to "identify" UFO sightings to calm the public hysteria about UFOs. This theory has been supported by the recent release of CIA documents pertaining to UFOs. They also suggest that any report that was initially perceived as unexplainable or would cause public concern was never included in Project Blue Book. They allege that these reports were passed on to a higher authority that never reported the results to the public. Project Blue Book, it seems, was just a low level collection and disinformation program created under Project Sign (of December 1947) which evolved into Project Grudge (of December 1948) to cover up the true investigation into the alien presence on Earth." From "United States Air Force Project Blue Book", Above Top Secret Website

Comprehensive Catalog of 1,500 Project BLUE BOOK UFO Unknowns (Version 1.1) (PDF Format)
Brad Sparks
Contains an extensive listing of 1,500 UFO sightings and cases from the US Air Force Project Bluebook files that remained 'unknown' or 'unidentified' after investigation. This is out of a total of 12,000. The original number of 'unknowns' in Project Bluebook was approx. 700, however this author has compiled an extended listing of 'unknowns' higher than the 'official' and original number of 700 'unknowns'. This catalog by the author contains 1,500 'unknowns' from Bluebook.

Project Blue Book Archive
The Project Blue Book Archive is a new web-site which will provide free online access to the National Archives Blue Book microfilm collection, and has so far posted about 10% of the Blue Book microfilm. The Blue Book Archive provides a fully searchable interface to high-resolution document scans relating to the US government's investigation of the UFO phenomena. Also available are high-quality CD-ROMs of the microfilms, which can be purchased directly from the website.

J. Allen Hynek on Project Blue Book
Excerpt from the book, "The UFO Experience - A Scientific Inquiry", by J. Allen Hynek
The popular impression through the years was that Blue Book was a full-fledged, serious operation. The public perhaps envisioned a spacious, well-staffed office with rows of file cabinets, a computer terminal for querying the UFO data bank, and groups of scientists quietly studying reports, attended by a staff of assistants. The actual situation was unfortunately the opposite. R

News article: 'Air Force closes study of UFO's'
New York Times, December 18, 1969
Article appearing in the New York Times reporting the closure of U.S. Air Force Project Blue Book. R

Project Blue Book
Loy Lawhon
Overviews of Project Grudge and Project Bluebook, by Loy Lawhon. R

Project Blue Book 1951-1969
Michael Hall, Project Blue Book Research Center
Overview and history of the United States Air Force's Project Blue Book, the official study of UFOs.

Project Blue Book Archives Go Online - Annoucement
William Wise, UFO Updates, 1/9/05
The purpose of this email is to introduce you to the Blue Book Archive. In brief, we have created a web-site which provides free online access to the National Archives Blue Book microfilm collection. Moreover, these documents have been rendered searchable so as to increase the utility of this material to researchers.

Project Blue Book Member Biographies
Project Blue Book Research Center

Project Bluebook "Unknowns"
Don Berliner, Fund for UFO Research
The unexplained UFO reports from the files of the U.S. Air Force's Project Blue Book UFO investigations. Compiled by Don Berliner, for the Fund for UFO Research. Contains the original 700 Project Bluebook 'Unknowns', i.e. UFO sightings and cases from Project Bluebook that remained 'unidentified' after investigation' (out of 12,000 cases). Includes brief summary descriptions of the sightings.

Projects Sign, Grudge and Blue Book
The WHY? Files

Should the USAF Reopen Project Blue Book?
1974 Air Command and Staff College Research Study, Air University, Report No. 0450-74
This study evaluates factors related to the USAF investigation of Unidentified Flying Objects in an attempt to determine whether or not additional UFO investigation is warranted. The approach to analysis taken by this study was twofold: one writer evaluated evidence justifying the closure of Project Blue Book while the other writer evaluated evidence supporting its reopening. Based on the evidence uncovered, the study concludes that there is a definite need for a new UFO investigation.

U.S. Air Force Fact Sheet on UFOs and Project Blue Book
U.S. Air Force (updated April 2003)
This is a current, official fact sheet by the U.S. Air Force regarding UFOs and Project Blue Book. R

What Our Air Force Found Out About UFOs
Captain Edward J. Ruppelt, USAF, True Magazine book-length feature
From 1951 to 1953 Mr. Ruppelt was in charge of Project Blue Book, the official Air force investigation of Unidentified Flying Objects. This is what he learned from them.

Project Blue Book Archive
The Project Blue Book Archive is a new web-site which will provide free online access to the National Archives Blue Book microfilm collection, and has so far posted about 10% of the Blue Book microfilm. The Blue Book Archive provides a fully searchable interface to high-resolution document scans relating to the US government's investigation of the UFO phenomena. Also available are high-quality CD-ROMs of the microfilms, which can be purchased directly from the website.

Project Blue Book Research Center
Devoted to the task of researching the historical aspects of the third official investigation of Unidentified Flying Objects by the United States Air Force.