Detection of 13C17O and Observations of Rare CO Isotopomers towards the r Ophiuchi Molecular Cloud Bensch, Frank ; Pak, Igor ; Wouterloot, Jan G. A. ; Klapper, Gabriele ; Winnewisser, Gisbert Abstract Publication: Astronomische Nachrichten Supplement Pub Date: July 2003 Bibcode: 2003ANS...324...62B