Williams, P., Colla, S., Richardson, L., & Thorp, R. W. (2014). Bumble Bees of North America: An Identification Guide. Princeton University Press.
Cita Chicago Style (17a ed.)Williams, Paul, Sheila Colla, Leif Richardson, y Robbin W. Thorp. Bumble Bees of North America: An Identification Guide. Princeton, N.J.: Princeton University Press, 2014.
Cita MLA (8a ed.)Williams, Paul, et al. Bumble Bees of North America: An Identification Guide. Princeton University Press, 2014.
Precaución: Estas citas no son 100% exactas.