Broadbent, Arthur, and Andrew Bourke. 2012. “The Bumblebee Bombus Hortorum Is the Main Pollinating Visitor to Digitalis Purpurea (Common Foxglove) in a U.K. Population”. Journal of Pollination Ecology 8 (May):48-51. https://doi.org/10.26786/1920-7603(2012)10.