Zhang, R.-N., C. V. Achterberg, X.-X. Tian, C.-Y. He, and J.-L. Tan. “Sexual Variation in Two Species of Helorus Latreille (Hymenoptera, Heloridae) from NW China, With Description of Female of Helorus caii He &Amp; Xu”. Zootaxa, vol. 4821, no. 3, Aug. 2020, pp. 570–584, doi:10.11646/zootaxa.4821.3.8.