Williams, P., Thorp, R. W., Richardson, L., & Colla, S. (2014). Bumble bees of North America: An identification guide. Princeton University Press.
Chicago Style (17th ed.) CitationWilliams, Paul, Robbin W. Thorp, Leif Richardson, and Sheila Colla. Bumble Bees of North America: An Identification Guide. Princeton, N.J.: Princeton University Press, 2014.
MLA (8th ed.) CitationWilliams, Paul, et al. Bumble Bees of North America: An Identification Guide. Princeton University Press, 2014.
Warning: These citations may not always be 100% accurate.