Beutler, Gerhard Methods of celestial mechanics vol.1, physical, mathematical and numerical principles Gerhard Beutler - Berlin Springer 2005 - xvi, 464p. - Astronomy and astrophysics library . ISBN: 3-540-40749-9 Subjects--Topical Terms: Celestial mechanicsTheory of perturbation Universal Decimal Class. No.: 521.1 / BEU-1