1. Beemorph© (2004) Bee wing morphometric analysis program. [online] http://www.hockerley.plus.com (accessed on 10 July 2006).
2. Cowan T.W. (1904) The honeybee; its natural history, anatomy and physiology, 2nd ed., Houlston and Sons, London, p. 220.
3. Grout R.A. (1937) The influence of the size of brood cell upon the size and variability of the honeybee (Apis melliferaL.), Iowa Agric. Exp. Sta. Bull. 216.