1Michael S, et al. Diurnal activity, floral visitation and pollen deposition by honey bees and bumble bees on field - grown cucumber and watermelon. Journal of Apicultural Research. 2002,40, (1-2): 27-34.
2Fisher and Pomeroy. Pollination of greenhouse muskmelons by bumble bees (Hymenoptera: Apidae). Journal of Economic Entomology. 1989, 82, (4): 1061- 1066.