Since the modern age of unidentified flying object incidents began in 1947, many organizations dedicated to the phenomena have formed (and disbanded). It can be a bit confusing to sort out the alphabet soup of UFO group acronyms, so this article attempts to introduce some of the most commonly encountered international organizations both past and present. If the group is currently active then online contact information is provided. All sites are in English except for the brief list of worldwide organizations at the end of the article.
APRO (Aerial Phenomena Research Organization): Founded by Jim and Coral Lorenzen in 1952, APRO was active until 1988. Based out of Arizona, APRO focused on using scientific techniques to investigate reports of unidentified flying objects. Dr. James E. McDonald, physicist and professor at the University of Arizona, Tucson, was one of several PhD level scientists that consulted with the group. APRO was involved with both the Travis Walton and Paul Bennewitz cases.