Reference
Shôichi Francisco Sakagami, Andreas Werner Ebmer (1996): Lasioglossum (Evylaeus) frigidum sp. nov., with taxonomic notes on the allied species of L. (E.) sexstrigatum group (Hymenoptera, Apoidea, Halictidae). – Linzer biologische Beiträge – 0028_2: 899 - 916.