Stabilized Kepler motion connected with analytic step adaptation

In the publication Baumgarte and Stiefel (1974a) a stabilization of the Keplerian motion was offered by making use of a manipulation of the Hamiltonian. By this stabilization technique the given HamiltonianH(pi,qi) is replaced by a new HamiltonianH*, which leads to Lyapunov-stable differential equations of motion.