1. 2Campbell, J. "A Technique Utilizing Free Flying Radio-Controlled Models to Study Incipient- and Developed-Spin Characteristics of Airplanes," AGARD Rept. 76,1959.
2. 4Thorn, R., Structural Stability and Morphogenesis, Addison-Wesley, Reading, Mass. 1974, pp.47,48, 55-92.