References
- DOULL, K. M. (1966) The relative attractiveness to pollen collecting honeybees of some different pollens. J. apic. Res. 5(1): 9–14
- DOULL, K. M. & STANDIFER, L. N. (1969) A technique for measuring feeding responses of honeybees in their hive. J. apic. Res. 8(3): 153–157