Buck, M., Marshall, S.A. and Cheung D.K.B. 2008. Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region. Canadian Journal of Arthropod Identification No. 5: 492 pp. (PDF version).
Published on 19 February 2008. With 3 Tables and 1073 Figures (doi: 10.3752/cjai.2008.05).

Available online at http://www.biology.ualberta.ca/bsc/ejournal/bmc_05/bmc_05.html.