1. N. A. Krall and W. Trivelpiece,Principle of Plasma Physics(McGraw-Hill, New York, 1973), p. 106.
2. S. Ichimaru,Basic Principles of Plasma Physics, A Statistical Approach(W. A. Benjamin, New York, 1973), p. 77.
3. Drift waves and instabilities
4. Propagation of Ion-Acoustic Solitary Waves of Small Amplitude