Discovery of weak 6.7 GHz CH3OH masers in a sample of high-mass Hi-GAL sources L. Olmi, E. D. Araya, P. Hofner, S. Molinari, J. Morales Ortiz, L. Moscadelli and M. Pestalozzi A&A, 566 (2014) A18 Published online: 02 June 2014 DOI: 10.1051/0004-6361/201322978