HESS upper limits on very high energy gamma-ray emission from the microquasar GRS 1915+105 - Acero, Fabio; Behera, Bagmeet; Hauser, Marcus; Kaufmann, Sarah; Pedaletti, Giovanna; Quirrenbach, Andreas; Schwemmer, Stephanie; Tam, Pak Hin; Wagner, Stefan (Astronomy and astrophysics, 2009)