One-loop effective action for non-local modified Gauss–Bonnet gravity in de Sitter spaceGuido Cognola, Emilio Elizalde, Shin’ichi Nojiri, Sergei D. Odintsov and Sergio ZerbiniEur. Phys. J. C, 64 3 (2009) 483-494DOI: https://doi.org/10.1140/epjc/s10052-009-1154-4