<ref name="Gregg_1945">{{cite journal |first1=R. E. |last1=Gregg |year=1945 |title=The ants of the Chicago region |url=https://antcat.org/documents/5004/11928.pdf |journal=Annals of the Entomological Society of America |publisher= |volume=37 |issue= |pages=447–480 |doi= }}</ref>