[1]
H.-J. Jacobs and J. Oehlke, “Beiträge zur Insektenfauna der DDR: Hymenoptera: Sphecidae. 1. Nachtrag”., contrib.entomol., vol. 40, no. 1, pp. 121–229, Dec. 1990, doi: 10.21248/contrib.entomol.40.1.121-229.