Pollination of Seed Crops by Insects (in Seeds. The Yearbook of Agriculture)
U.S. Government Printing Office
Pollination and foraging
Bohart, G. E., and Frank E. Todd. 1961. Pollination of Seed Crops by Insects. In Seeds. The Yearbook of Agriculture. U.S. Givernment Printing Office, Washington, D.C. p. 240-246.
This document is currently not available here.