Richardson, Leif L. books & textbook
Bumble Bees of North America: An Identification Guide (Princeton Field Guides, 89)
Williams, Paul H. Thorp, Robbin W. Richardson, Leif L. Colla, Sheila R.
Princeton University Press /2014-03-30 Paperback / 208 Pages
isbn-10: 0691152225 / isbn-13: 9780691152226