1. A geometrical study of re-entry transfer orbits;Vinh,1963
2. Deboost from circular orbits;Milstead;AAS J.,1966
3. On optimal transfer between two terminal points for minimum initial impulse under an arbitrary initial velocity vector;Sun;NASA CR-622,1966
4. Geometric theory of optimum disorbit problems;Busemann;NASA CR-750,1967
5. Analysis of the optimum two-impulses orbital transfer under arbitrary terminal conditions;Sun;AIAA J.,1968