PT Unknown AU de Graauw, T Caux, E Guesten, R Helmich, F Pearson, J Phillips, TG Schieder, R Tielens, X Saraceno, P Stutzki, J Wafelbakker, CK Whyborn, ND TI The Herschel-heterodyne instrument for the far-infrared (HIFI) SE Bulletin of the American Astronomical Society PY 2005 BP 1219 VL 37 ER