"Theory of Orbits" was described in a 1968 academic review as a "complete discussion of the basic results that have been established concerning the restricted circular problems of three bodies." It is considered an important work in the field of celestial mechanics, as well as an essential text on the restricted three-body problem posed by situations such as orbiting satellites and Earth-to-Moon spacecraft missions.
The first nine chapters address the restricted plane orbital problem of three points, and the final chapter deals with other restrictive problems. The restricted three-body problem assumes that in a single plane accommodating three interacting bodies, the mass of the smallest object is negligible, and therefore it will not influence the motion of the larger bodies following circular orbits.
Szebehely's work tackles the problem of how to monitor the motion of a third body of insignificant size in any particular plane. It also addresses the flaws in theories constructed by previous mathematicians who attempt to solve this problem.