[1]
A. Bertsch, H. Schweer, and A. Titze, “Discrimination of the bumblebee species Bombus lucorum, Bombus cryptarum and Bombus magnus by morphological characters and male labial gland secretions (Hymenoptera: Apidae)”., contrib.entomol., vol. 54, no. 2, pp. 365–386, Dec. 2004, doi: 10.21248/contrib.entomol.54.2.365-386.