Reference

Karl Crailsheim, L.H.W. Schneider, H. Hrassnigg, G. Bühlmann, U. Brosch, R. Gmeinbauer, B. Schöffmann (1992): Pollen consumption and utilisation in worker honey bees: dependence on individual age and function. – J.Insect Physiol. – 38: 409 - 419.