Cole, M.L. and Herbert, D.G. 2023. Seven new narrowly endemic species of Gulella Pfeiffer, 1856 from eastern South Africa (Gastropoda, Streptaxidae) and status revision for another. European Journal of Taxonomy. 900, 1 (Oct. 2023), 1–31. DOI:https://doi.org/10.5852/ejt.2023.900.2299.