Cruciol, A.H., Noll, F.B., Stange, L.A. and Lopes, R.B. 2026. Five new species of the Zethus spinosus species group (Hymenoptera, Vespidae, Eumeninae, Zethus). Zootaxa. 5748, 1 (Jan. 2026), 56–72. DOI:https://doi.org/10.11646/zootaxa.5748.1.2.