Molecules in bipolar proto-planetary nebulae P. M. Woods, L.-Å. Nyman, F. L. Schöier, A. A. Zijlstra, T. J. Millar and H. Olofsson A&A, 429 3 (2005) 977-992 Published online: 05 January 2005 DOI: 10.1051/0004-6361:20034388