An indication of anisotropy in arrival directions of ultra-high-energy cosmic rays through comparison to the flux pattern of extragalactic gamma-ray sources - Aab, A.; Albuquerque, Ivone Freire da Mota e; Catalani, Fernando; Souza, Vitor de; Kemmerich, N.; Lang, R. G.; Prado, R. R.; Carvalho, W. Rodrigues de; Santos, Edivaldo Moura; Peixoto, Carlos Jose Todero (Astrophysical Journal Letters, 2018)