1. Critical velocity experiments in space
2. Simultaneous comparison of RF probe techniques for determination of ionospheric electron density
3. 4Ramo, S., Whinnery, J. R., and Van Duzer, T., Electromagnetic Fields and Waves in Communication Electronics, 2nd ed.Wiley, New York, 1984, pp.191-193.
4. 5Jensen, M.D. "Investigation of Accuracy Limitations of the Ionospheric Plasma Frequency Probe and Recommendations for a New Instrument," M.S. Thesis,Utah State Univ., Logan, UT, May 1988.