Lobo, J. M., B. V. Guéorguiev, and E. I. Chehlarov. “The Species of <i>Scarabaeus</i> Linnaeus (Coleoptera: Scarabaeidae) in Bulgaria and Adjacent Regions: Faunal Review and Potential Distribution”. Entomologica Fennica, vol. 21, no. 4, Feb. 2011, pp. 202–220, doi:10.33338/ef.3932.