The structure and dynamics of the molecular envelope of M 2-56 A. Castro-Carrizo, V. Bujarrabal, C. Sánchez Contreras, J. Alcolea and R. Neri A&A, 386 2 (2002) 633-645 Published online: 15 May 2002 DOI: 10.1051/0004-6361:20020220