1. Transferts économiques entre orbites infiniment proches;Marec,1966
2. J.P. Marec, Transferts optimaux entre orbites elliptiques proches, ONERA Publication No. 121, 1967; Optimal transfers between close elliptical orbits, NASA T.T. F. 554, 1969.
3. Optimal variable-thrust transfer of a power-limited rocket between neighbouring circular orbits;Gobetz;AIAA J.,1964
4. A linear theory of optimum low-thrust rendezvous trajectories;Gobetz;J. Astronaut. Sci.,1965
5. Linearized treatment of the optimal transfer of a thrust-limited vehicle between coplanar circular orbits;McIntyre;Astronaut. Acta,1966