Ultrahigh-energy neutrino follow-up of gravitational wave events GW150914 and GW151226 with the Pierre Auger Observatory - Aab, A.; Albuquerque, Ivone Freire da Mota e; Souza, Vitor de; Gouffon, Philippe; Prado, R. R.; Carvalho, W. Rodrigues de; Santos, Edivaldo Moura; Peixoto, Carlos Jose Todero (Physical Review D, 2016)