Reference
Tadeusz Pawlikowski, Piotr Olszewski, Waldemar Zyla, Magdalena Przybylinska (2016): Scientific note: The rare oligolectic bumblebee Bombus gerstaeckeri Morawitz, 1882 from Poland (Hymenoptera, Apidae) – Spixiana, Zeitschrift für Zoologie – 039: 130.