1. Moulton, F R , An Introduction to Celestial Mechanics (The Macmillan Company, New York, 1914), p146
2. Davis, H T , Introduction to Nonlinear Differential and Integral Equations (Dover Publications, Inc, New York, 1962), p145
3. Talbot, L , "Criterion for slip near the leading edge of a flat plate in hypersonic flow/' AIAA J 1, 1169-1171 (1963)