The energy spectrum of cosmic rays beyond the turn-down around 10' POT. 17' eV as measured with the surface detector of the Pierre Auger Observatory - Abreu, P.; Arbeletche, Luan Bonneau; Catalani, Fernando; Souza, Vitor de; Lang, Rodrigo Guedes; Martínez-Huerta, Humberto; Armand, Johnnier Pérez; Carvalho Junior, Washington Rodrigues de; Santos, Edivaldo Moura; Peixoto, Carlos Jose Todero (European Physical Journal C, 2021)