Detection of atmospheric muon neutrinos with the IceCube 9-string detector - Achterberg, A; Ackermann, M; Adams, J; Ahrens, J; Andeen, K; Auffenberg, J; Bai, X; Baret, B; Barwick, SW; Bay, R; Beattie, K; Becka, T; et al. (PHYSICAL REVIEW D, 2007)