Acute normobaric hyperoxia transiently attenuates plasma erythropoietin concentration in healthy males: evidence against the ‘normobaric oxygen paradox’ theory - Keramidas, M E; Kounalakis, S N; Debevec, T; Norman, B; Gustafsson, T; Eiken, O; Mekjavic, I B (Acta Physiol (Oxf), 2011)