Discovery of hard-spectrum γ-ray emission from the BL Lacertae object 1ES 0414+009 - Abramowski, Attila; Behera, Bagmeet; Becherini, Yvonne; Cologna, Gabriele; Hauser, Marcus; Kaufmann, Sarah; Pühlhofer, Gerd; Quirrenbach, Andreas; Schwemmer, Stephanie; Wagner, Stefan (Astronomy and astrophysics, 2012)