This collection includes correspondence, articles, newsclippings, photographs, and recordings, concerning Menzel's documentation of UFOs as natural phenomena explainable in scientific terms. One can find material on the National Investigation Committee on Aerial Phenomena, Project Blue Book, the Velikovsky controversy, and a card file of meteor activity, 1946-1961.
Donald Howard Menzel's Autobiography is also located in the American Philosophical Society Library (Mss.B.M522).
- National Investigations Committee on Aerial Phenomena.
- Project Blue Book (U.S.)
- Card files.
- Botley, Cicely Mary
- Boyd, Lyle Gifford, 1907-
- Condon, Edward Uhler, 1902-1974
- Hynek, J. Allen, (Joseph Allen), 1910-1986
- Keyhoe, Donald E., (Donald Edward), 1897-
- Klass, Philip J.
- Maney, Charles Albert, 1891-
- Markowitz, William
- Menzel , Donald Howard, 1901-1976
- Quintanella, Hector
- Sagan, Carl, 1934-1996
- Schreibsten, Norman
- Velikovsky, Immanuel, 1895-1979
- Wellman, Wade
- Unidentified flying objects.