Cely, C. C., and C. E. Sarmiento. “What about Intraspecific Variation? Reassessment of Taxonomic and Phylogenetic Characters in the Genus Synoeca De Saussure (Hymenoptera: Vespidae: Polistinae)”. Zootaxa, vol. 2899, no. 1, May 2011, pp. 43–59, doi:10.11646/zootaxa.2899.1.2.