The highly collimated bipolar outflow of OH 231.8+4.2 J. Alcolea, V. Bujarrabal, C. Sánchez Contreras, R. Neri and J. Zweigle A&A, 373 3 (2001) 932-949 Published online: 15 July 2001 DOI: 10.1051/0004-6361:20010535