@article{articlec94b4a91,
title   = {Resonance in regular variables: I. Morphogenetic analysis of the orbits in the case of a first-order resonance},
author = {Ferraz-Mello, Sylvio},
year = {1985},
doi = {10.1007/bf01227653},
journal   = {Celestial Mechanics & Dynamical Astronomy}
}