File:Seifert, B. 1992. Formica nigricans - an ecomorph of Formica pratensis.pdf

Summary
Seifert, B. 1992. Formica nigricans Emery 1909 - an ecomorph of Formica pratensis Retzius, 1783 (Hymenoptera, Formicidae). Entomologica Fennica 2: 217-226.