Seifert, Bernhard. “<i>Formica nigricans</i> Emery, 1909 - an Ecomorph of <i>Formica pratensis</I> Retzius, 1783 (Hymenoptera, Formicidae)”. Entomologica Fennica 2, no. 4 (December 1, 1991): 217–226. Accessed November 23, 2024. https://journal.fi/entomolfennica/article/view/83554.