Herschel/PACS spectroscopy of trace gases of the stratosphere of Titan M. Rengel, H. Sagawa, P. Hartogh, E. Lellouch, H. Feuchtgruber, R. Moreno, C. Jarchow, R. Courtin, J. Cernicharo and L. M. Lara A&A, 561 (2014) A4 Published online: 17 December 2013 DOI: 10.1051/0004-6361/201321945