[VIII-1] Keyhoe, D. E. The Flying Saucer Conspiracy. New York: Henry Holt & Co., 1955.

[VIII-2] Air Force Files.

[VIII-3] Ruppelt, E. J. The Report on Unidentified Flying Objects. Garden City, N.Y.: Doubleday & Co., 1956.

[VIII-4] Plank, V. G. “Spurious Echoes on Radar, A Survey.” Astia Document No. AD-215470, AFCRC-TR-59-210 (May 1959).

[VIII-5] Borden, R. C., and Vickers, T. K. “A Preliminary Study of Unidentified Targets Observed on Air Traffic Control Radars.” Technical Development Report No. 180, Civil Aeronautics Administration, Technical Development and Evaluation Center, Indianapolis, Indiana (May 1953).

[VIII-6] “Radar Objects Over Washington,” Air Weather Service Bulletin (September 1954), pp. 52–57.

[VIII-7] Menzel, D. H. Elementary Manual of Radio Propagation. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1948.

[VIII-7a] —— “Why Flying Saucers Show Up on Radar.” Look magazine (September 9, 1952).

[VIII-8] Keyhoe, D. E. “What Radar Tells about Flying Saucers.” True magazine (December 1952), p. 25 ff.

[VIII-9] Plank, V. G. Personal communication.

[VIII-10] Withrow, S. R. “Angels on Radar Scopes,” Air Weather Service Bulletin (September 1954), pp. 48–51.

[VIII-11] Atlas, D. “Radar Studies of Meteorological ‘Angel’ Echoes,” Journal of Atmospheric and Terrestrial Physics, Vol. XV (1959), pp. 262–87.

[VIII-12] —— “Possible Key to the Dilemma of Meteorological ‘Angel’ Echoes,” Journal of Meteorology, Vol. XVII (1960), pp. 95–103.

[VIII-13] —— “Sub-horizon Radar Echoes by Scatter Propagation,” Journal of Geophysical Research, Vol. LXIV (1959), pp. 1205–18.

[VIII-14] Richardson, R. E.; Stacey, J. M.; Kohler, H. M.; and Naka, F. R., “Radar Observations of Birds,” Proceedings of the Seventh Weather Radar Conference (November 1958).

[VIII-15] Harper, W. G. “Angels on Centimetric Radars Caused by Birds,” Nature, Vol. CLXXX (1957), p. 847.

[VIII-16] Ligda, M. G. H. “Radar Observations of Blackbird Flights,” Texas Journal of Science (December 1958).

[VIII-17] Holzer, R., and Smith, W. (Eds.), Proceedings on the Conference on Atmospheric Electricity, Geophysics Research Directorate, Air Force Cambridge Research Center, AFCRC-TR-55-222 (December 1955).

[VIII-18] Eastwood, E; Bell, J. D.; and Phelp, N. R. “‘Ring Angels’ over Southeast England,” Nature, Vol. CLXXXIII (1959), pp. 1759–60.