1. Astronautical Guidance;Battin,1964
2. “Take-off from a circular orbit,”;Tsien;ARS J.,1953
3. “Asymptotic expansions of Navier-Stokes solutions for small Reynolds numbers,”;Kaplun;J. Math. & Mech.,1957
4. “On take-off from a circular orbit by a small thrust,”;Ting,1962
5. Asymptotic Methods in the Theory of Nonlinear Oscillations;Bogoliubov,1961