It is indeed a pleasure to thank the many people who helped me in various ways during preparation of this book. First of all, to each of the many eye witnesses of these events goes my gratitude and respect for their courage to report their experiences in the first place, particularly to Mr. Francis P. Wall. It will partially be through such brave acts that we will, one day, discover the core identity of the so-called UFO phenomenon. In addition, the following persons deserve my sincere thanks.

            To the Archives Division of the Smithsonian Institution's National Air and Space Museum for permission to reproduce selected photographs of combat aircraft. To John P. Timmerman Vice President of Public Relations for the J. Allen Hynek Center for UFO Studies for obtaining part of the interview material in Chapter Two. To Loren Gross for his able assistance in locating some US AF Project Blue Book reports as well as old newspaper clippings. To David L. Black, Director of Public Affairs, Defense Mapping Agency for helpful advice on how to obtain charts from the Korean War period. To Lt. Col. Clayton R. Newell, Chief Historical Systems Division, Department of the Army. To the Chief of Military History at the Center of Military History who provided valuable suggestions on how to obtain further wartime data. To John R. Gerfen, Chief, Army Reference Branch, National Personnel Records Center for copies of wartime unit personnel rosters. Finally, I am grateful to my wife Carol for her expert editorial assistance which made this text far more readable than it otherwise would have been.