Literature
- Else, G.R. & Edwards, M. 2018. Handbook of the Bees of the British Isles. Ray Society, London.
- Falk, S. 1991. A review of the scarce and threatened bees, wasps and ants of Great Britain. Research and Survey in Nature Conservation 35: 1-344.
- Knuth, P. 1908. Handbook of Flower Pollination, Vol. II. Clarendon Press, Oxford p652.
- Nieto, A., Roberts, S.P.M., Kemp, J., Rasmont, P., Kuhlmann, M., García Criado, M., Biesmeijer, J.C., Bogusch, P., Dathe, H.H., De la Rúa, P., De Meulemeester, T., Dehon, M., Dewulf, A., Ortiz-Sánchez, F.J., Lhomme, P., Pauly, A., Potts, S.G., Praz, C., Quaranta, M., Radchenko, V.G., Scheuchl, E., Smit, J., Straka, J., Terzo, M., Tomozii, B., Window, J. and Michez, D. 2014. European Red List of bees. Luxembourg: Publication Office of the European Union.Wind, P. & Pihl, S. (eds.) 2010: The Danish Red List. - The National Environmental Research Institute, Aarhus University [2004]-. http://redlist.dmu.dk (updated April 2010).
- Wüstenei, W. 1891. Beiträge zur Insektenfauna Schleswig-Holsteins (drittes Stück). Schr. Naturwiss. Ver. Schlesw-Holst. 8(1), 25-42.