@article{article0dc484c7,
title   = {Dynamics of two planets in the 2/1 mean-motion resonance},
author = {Callegari Júnior, Nelson and Michtchenko, Tatiana Alexandrovna and Ferraz-Mello, Sylvio},
year = {2004},
journal   = {Celestial Mechanics and Dynamical Astronomy}
}