Génier, F. Three New Species of Onthophagus Latreille, 1802 from Bioko Island, Equatorial Guinea, Belonging to d’Orbigny’s Group IX, With a Taxonomic Note on O. denudatus D’Orbigny, 1902 (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini). Zootaxa 2026, 5831, 413-426.